Journal tags: css

114

sparkline

Custom properties

I made the website for the Clearleft podcast last week. The design is mostly lifted straight from the rest of the Clearleft website. The main difference is the masthead. If the browser window is wide enough, there’s a background image on the right hand side.

I mostly added that because I felt like the design was a bit imbalanced without something there. On the home page, it’s a picture of me. Kind of cheesy. But the image can be swapped out. On other pages, there are different photos. All it takes is a different class name on that masthead.

I thought about having the image be completely random (and I still might end up doing this). I’d need to use a bit of JavaScript to choose a class name at random from a list of possible values. Something like this:

var names = ['jeremy','katie','rich','helen','trys','chris'];
var name = names[Math.floor(Math.random() * names.length)];
document.querySelector('.masthead').classList.add(name);

(You could paste that into the dev tools console to see it in action on the podcast site.)

Then I read something completely unrelated. Cassie wrote a fantastic article on her site called Making lil’ me - part 1. In it, she describes how she made the mouse-triggered animation of her avatar in the footer of her home page.

It’s such a well-written technical article. She explains the logic of what she’s doing, and translates that logic into code. Then, after walking you through the native code, she shows how you could use the Greeksock library to achieve the same effect. That’s the way to do it! Instead of saying, “Here’s a library that will save you time—don’t worry about how it works!”, she’s saying “Here’s it works without a library; here’s how it works with a library; now you can make an informed choice about what to use.” It’s a very empowering approach.

Anyway, in the article, Cassie demonstrates how you can use custom properties as a bridge between JavaScript and CSS. JavaScript reads the mouse position and updates some custom properties accordingly. Those same custom properties are used in CSS for positioning. Voila! Now you’ve got the position of an element responding to mouse movements.

That’s what made me think of the code snippet I wrote above to update a class name from JavaScript. I automatically thought of updating a class name because, frankly, that’s how I’ve always done it. I’d say about 90% of the DOM scripting I’ve ever done involves toggling the presence of class values: accordions, fly-out menus, tool-tips, and other progressive disclosure patterns.

That’s fine. But really, I should try to avoid touching the DOM at all. It can have performance implications, possibly triggering unnecessary repaints and reflows.

Now with custom properties, there’s a direct line of communication between JavaScript and CSS. No need to use the HTML as a courier.

This made me realise that I need to be aware of automatically reaching for a solution just because that’s the way I’ve done something in the past. I should step back and think about the more efficient solutions that are possible now.

It also made me realise that “CSS variables” is a very limiting way of thinking about custom properties. The fact that they can be updated in real time—in CSS or JavaScript—makes them much more powerful than, say, Sass variables (which are more like constants).

But I too have been guilty of underselling them. I almost always refer to them as “CSS custom properties” …but a lot of their potential comes from the fact that they’re not confined to CSS. From now on, I’m going to try calling them custom properties, without any qualification.

Dark mode revisited

I added a dark mode to my website a while back. It was a fun thing to do during Indie Web Camp Amsterdam last year.

I tied the colour scheme to the operating system level. If you choose a dark mode in your OS, my website will adjust automatically thanks to the prefers-color-scheme: dark media query.

But I’ve seen notes from a few friends, not about my site specifically, but about how they like having an explicit toggle for dark mode (as well as the media query). Whenever I read those remarks, I’d think “I’m really not sure I’ve got time to deal with adding that kind of toggle to my site.”

But then I realised, “Jeremy, you absolute muffin! You’ve had a theme switcher on your website for almost two decades now!”

Doh! I had forgotten about that theme switcher. It dates back to the early days of CSS. I wanted my site to be a demonstration of how you could apply different styles to the same underlying markup (this was before the CSS Zen Garden came along). Those themes are very dated now, but if you like you can view my site with a Zeldman theme or a sci-fi theme.

To offer a dark-mode theme for my site, all I had to do was take the default stylesheet, pull out the custom properties from the prefers-color-scheme: dark media query, and done. It took less than five minutes.

So if you want to view my site in dark mode, it’s one of the options in the “Customise” dropdown on every page of the website.

CSS custom properties and the cascade

When I wrote about programming CSS to perform Sass colour functions I said this about the brilliant Lea Verou:

As so often happens when I’m reading something written by Lea—or seeing her give a talk—light bulbs started popping over my head (my usual response to Lea’s knowledge bombs is either “I didn’t know you could do that!” or “I never thought of doing that!”).

Well, it happened again. This time I was reading her post about hybrid positioning with CSS variables and max() . But the main topic of the post wasn’t the part that made go “Huh! I never knew that!”. Towards the end of her article she explained something about the way that browsers evaluate CSS custom properties:

The browser doesn’t know if your property value is valid until the variable is resolved, and by then it has already processed the cascade and has thrown away any potential fallbacks.

I’m used to being able to rely on the cascade. Let’s say I’m going to set a background colour on paragraphs:

p {
  background-color: red;
  background-color: color(display-p3 1 0 0);
}

First I’ve set a background colour using a good ol’ fashioned keyword, supported in browsers since day one. Then I declare the background colour using the new-fangled color() function which is supported in very few browsers. That’s okay though. I can confidently rely on the cascade to fall back to the earlier declaration. Paragraphs will still have a red background colour.

But if I store the background colour in a custom property, I can no longer rely on the cascade.

:root {
  --myvariable: color(display-p3 1 0 0);
}
p {
  background-color: red;
  background-color: var(--myvariable);
}

All I’ve done is swapped out the hard-coded color() value for a custom property but now the browser behaves differently. Instead of getting a red background colour, I get the browser default value. As Lea explains:

…it will make the property invalid at computed value time.

The spec says:

When this happens, the computed value of the property is either the property’s inherited value or its initial value depending on whether the property is inherited or not, respectively, as if the property’s value had been specified as the unset keyword.

So if a browser doesn’t understand the color() function, it’s as if I’ve said:

background-color: unset;

This took me by surprise. I’m so used to being able to rely on the cascade in CSS—it’s one of the most powerful and most useful features in this programming language. Could it be, I wondered, that the powers-that-be have violated the principle of least surprise in specifying this behaviour?

But a note in the spec explains further:

Note: The invalid at computed-value time concept exists because variables can’t “fail early” like other syntax errors can, so by the time the user agent realizes a property value is invalid, it’s already thrown away the other cascaded values.

Ah, right! So first of all browsers figure out the cascade and then they evaluate custom properties. If a custom property evaluates to gobbledygook, it’s too late to figure out what the cascade would’ve fallen back to.

Thinking about it, this makes total sense. Remember that CSS custom properties aren’t like Sass variables. They aren’t evaluated once and then set in stone. They’re more like let than const. They can be updated in real time. You can update them from JavaScript too. It’s entirely possible to update CSS custom properties rapidly in response to events like, say, the user scrolling or moving their mouse. If the browser had to recalculate the cascade every time a custom property didn’t evaluate correctly, I imagine it would be an enormous performance bottleneck.

So even though this behaviour surprised me at first, it makes sense on reflection.

I’ve probably done a terrible job explaining the behaviour here, so I’ve made a Codepen. Although that may also do an equally terrible job.

(Thanks to Amber for talking through this with me and encouraging me to blog about it. And thanks to Lea for expanding my mind. Again.)

Programming CSS to perform Sass colour functions

I wrote recently about moving away from Sass to using native CSS features. I had this to say on the topic of mixins in Sass:

These can be very useful, but now there’s a lot that you can do just in CSS with calc(). The built-in darken() and lighten() mixins are handy though when it comes to colours.

I know we will be getting these in the future but we’re not there yet with CSS.

Anyway, I had all this in the back of my mind when I was reading Lea’s excellent feature in this month’s Increment: A user’s guide to CSS variables. She’s written about a really clever technique of combining custom properites with hsl() colour values for creating colour palettes. (See also: Una’s post on dynamic colour theming with pure CSS.)

As so often happens when I’m reading something written by Lea—or seeing her give a talk—light bulbs started popping over my head (my usual response to Lea’s knowledge bombs is either “I didn’t know you could do that!” or “I never thought of doing that!”).

I immediately set about implementing this technique over on The Session. The trick here is to use separate custom properties for the hue, saturation, and lightness parts of hsl() colour values. Then, when you want to lighten or darken the colour—say, on hover—you can update the lightness part.

I’ve made a Codepen to show what I’m doing.

Let’s say I’m styling a button element. I make custom propertes for hsl() values:

button {
  --button-colour-hue: 19;
  --button-colour-saturation: 82%;
  --button-colour-lightness: 38%;
  background-color: hsl(
    var(--button-colour-hue),
    var(--button-colour-saturation),
    var(--button-colour-lightness)
  );
}

For my buttons, I want the borders to be slightly darker than the background colour. When I was using Sass, I used the darken() function to this. Now I use calc(). Here’s how I make the borders 10% darker:

border-color: hsl(
  var(--button-colour-hue),
  var(--button-colour-saturation),
  calc(var(--button-colour-lightness) - 10%)
);

That calc() function is substracting a percentage from a percentage: 38% minus 10% in this case. The borders will have a lightness of 28%.

I make the bottom border even darker and the top border lighter to give a feeling of depth.

On The Session there’s a “cancel” button style that’s deep red.

Here’s how I set its colour:

.cancel {
  --button-colour-hue: 0;
  --button-colour-saturation: 100%;
  --button-colour-lightness: 40%;
}

That’s it. The existing button declarations take care of assigning the right shades for the border colours.

Here’s another example. Site admins see buttons for some actions only available to them. I want those buttons to have their own colour:

.admin {
  --button-colour-hue: 45;
  --button-colour-saturation: 100%;
  --button-colour-lightness: 40%;
}

You get the idea. It doesn’t matter how many differently-coloured buttons I create, the effect of darkening or lightening their borders is all taken care of.

So it turns out that the lighten() and darken() functions from Sass are available to us in CSS by using a combination of custom properties, hsl(), and calc().

I’m also using this combination to lighten or darken background and border colours on :hover. You can poke around the Codepen if you want to see that in action.

I love seeing the combinatorial power of these different bits of CSS coming together. It really is a remarkably powerful programming language.

Sass and clamp

CSS got some pretty nifty features recently. There’s the min() and max() functions. If you use them for, say, width you can use one rule where previously you would’ve needed to use two (a width declaration followed by either min-width or max-width). But they can also be applied to font-size! That’s very nifty—we’ve never had min-font-size or max-font-size properties.

There’s also the clamp() function. That allows you to set a minimum size, a default size, and a maximum size. Again, it can be used for lengths, like width, or for font-size.

Over on thesession.org, I’ve had some media queries in place for a while now that would increase the font-size for larger screens. It’s nothing crucial, just a nice-to-have so that on wide screens, the font is bumped up accordingly. I realised I could replace all those media queries with one clamp() statement, thanks to the vw (viewport width) unit:

font-size: clamp(1rem, 1.333vw, 1.5rem);

By default, the font-size is 1.333vw (1.333% of the viewport width), but it will never get smaller than 1rem and it will never get larger than 1.5rem.

That works, but there’s a bit of an issue with using raw vw units like that. If someone is on a wide screen and they try to adjust the font size, nothing will happen. The viewport width doesn’t change when you bump the font size up or down.

The solution is to mix in some kind of unit that does respond to the font size being bumped up or down (like, say, the rem unit). Handily, clamp() allows you to combine units, just like calc(). So I can do this:

font-size: clamp(1rem, 0.5rem + 0.666vw, 1.5rem);

The result is much the same as my previous rule, but now—thanks to the presence of that 0.5rem value—the font size responds to being adjusted by the user.

You could use a full 1rem in that default value:

font-size: clamp(1rem, 1rem + 0.333vw, 1.5rem);

…but if you do that, the minimum size (1rem) will never be reached—the default value will always be larger. So in effect it’s no different than saying:

font-size: min(1.rem + 0.333vw, 1.5rem);

I mentioned this to Chris just the other day.

Anyway, I got the result I wanted. I wanted the font size to stay at the browser default size (usually 16 pixels) until the screen was larger than around 1200 pixels. From there, the font size gets gradually bigger, until it hits one and a half times the browser default (which would be 24 pixels if the default size started at 16). I decided to apply it to the :root element (which is html) using percentages:

:root {
  font-size: clamp(100%, 50% + 0.666vw, 150%);
}

(My thinking goes like this: if we take a screen width of 1200 pixels, then 1vw would be 12 pixels: 1200 divided by 100. So for a font size of 16 pixels, that would be 1.333vw. But because I’m combining it with half of the default font size—50% of 16 pixels = 8 pixels—I need to cut the vw value in half as well: 50% of 1.333vw = 0.666vw.)

So I’ve got the CSS rule I want. I dropped it in to the top of my file and…

I got an error.

There was nothing wrong with my CSS. The problem was that I was dropping it into a Sass file (.scss).

Perhaps I am showing my age. Do people even use Sass any more? I hear that post-processors usurped Sass’s dominance (although no-one’s ever been able to explain to me why they’re different to pre-processers like Sass; they both process something you’ve written into something else). Or maybe everyone’s just writing their CSS in JS now. I hear that’s a thing.

The Session is a looooong-term project so I’m very hesitant to use any technology that won’t stand the test of time. When I added Sass into the mix, back in—I think—2012 or so, I wasn’t sure whether it was the right thing to do, from a long-term perspective. But it did offer some useful functionality so I went ahead and used it.

Now, eight years later, it was having a hard time dealing with the new clamp() function. Specifically, it didn’t like the values being calculated through the addition of multiple units. I think it was clashing with Sass’s in-built ability to add units together.

I started to ask myself whether I should still be using Sass. I looked at which features I was using…

Variables. Well, now we’ve got CSS custom properties, which are even more powerful than Sass variables because they can be updated in real time. Sass variables are like const. CSS custom properties are like let.

Mixins. These can be very useful, but now there’s a lot that you can do just in CSS with calc(). The built-in darken() and lighten() mixins are handy though when it comes to colours.

Nesting. I’ve never been a fan. I know it can make the source files look tidier but I find it can sometimes obfuscate what you’re final selectors are going to look like. So this wasn’t something I was using much any way.

Multiple files. Ah! This is the thing I would miss most. Having separate .scss files for separate interface elements is very handy!

But globbing a bunch of separate .scss files into one .css file isn’t really a Sass task. That’s what build tools are for. In fact, that’s what I was already doing with my JavaScript files; I write them as individual .js files that then get concatenated into one .js file using Grunt.

(Yes, this project uses Grunt. I told you I was showing my age. But, you know what? It works. Though seeing as I’m mostly using it for concatenation, I could probably replace it with a makefile. If I’m going to use old technology, I might as well go all the way.)

I swapped out Sass variables for CSS custom properties, mixins for calc(), and removed what little nesting I was doing. Then I stripped the Sass parts out of my Grunt file and replaced them with some concatenation and minification tasks. All of this makes no difference to the actual website, but it means I’ve got one less dependency …and I can use clamp()!

Remember a little while back when I was making a dark mode for my site? I made this observation:

Let’s just take a moment here to pause and reflect on the fact that we can now use CSS to create all sorts of effects that previously required a graphic design tool like Photoshop.

It feels like something similar has happened with tools like Sass. Sass was the hare. CSS is the tortoise. Sass blazed the trail, but now native CSS can achieve much the same result.

It’s like when we used to need something like jQuery to do DOM Scripting succinctly using CSS selectors. Then we got things like querySelector() in JavaScript so we no longer needed the trailblazer.

I’ve said it before and I’ll say it again, the goal of any good library should be to get so successful as to make itself redundant. That is, the ideas and functionality provided by the tool are so useful and widely adopted that the native technologies—HTML, CSS, and JavaScript—take their cue from those tools.

You could argue that this is what happened with Flash. It certainly happened with jQuery and Sass. I’m pretty sure we’ll see the same cycle play out with frameworks like React.

Oh, embed!

I wrote yesterday about how messing about on your own website can be a welcome distraction. I did some tinkering with adactio.com on the weekend that you might be interested in.

Let me set the scene…

I’ve started recording and publishing a tune a day. I grab my mandolin, open up Quicktime and make a movie of me playing a jig, a reel, or some other type of Irish tune. I include a link to that tune on The Session and a screenshot of the sheet music for anyone who wants to play along. And I embed the short movie clip that I’ve uploaded to YouTube.

Now it’s not the first time I’ve embedded YouTube videos into my site. But with the increased frequency of posting a tune a day, the front page of adactio.com ended up with multiple embeds. That is not good for performance—my Lighthouse score took quite a hit. Worst of all, if a visitor doesn’t end up playing an embedded video, all of the markup, CSS, and JavaScript in the embedded iframe has been delivered for nothing.

Meanwhile over on The Session, I’ve got a strategy for embedding YouTube videos that’s better for performance. Whenever somebody posts a link to a video on YouTube, the thumbnail of the video is embedded. Only when you click the thumbnail does that image get swapped out for the iframe with the video.

That’s what I needed to do here on adactio.com.

First off, I should explain how I’m embedding things generally ‘round here. Whenever I post a link or a note that has a URL in it, I run that URL through a little PHP script called getEmbedCode.php.

That code checks to see if the URL is from a service that provides an oEmbed endpoint. A what-Embed? oEmbed!

oEmbed is like a minimum viable read-only API. It was specced out by Leah and friends years back. You ping a URL like this:

http://example.com/oembed?url=https://example.com/thing

In this case http://example.com/oembed is the endpoint and url is the value of a URL from that provider. Here’s a real life example from YouTube:

https://www.youtube.com/oembed?url=https://www.youtube.com/watch?v=-eiqhVmSPcs

So https://www.youtube.com/oembed is the endpoint and url is the address of any video on YouTube.

You get back some JSON with a pre-defined list of values like title and html. That html payload is the markup for your embed code.

By default, YouTube sends back markup like this:

<iframe
width="480"
height="270"
src="https://www.youtube.com/embed/-eiqhVmSPcs?feature=oembed"
frameborder="0
allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture"
allowfullscreen>
</iframe>

But now I want to use an img instead of an iframe. One of the other values returned is thumbnail_url. That’s the URL of a thumbnail image that looks something like this:

https://i.ytimg.com/vi/-eiqhVmSPcs/hqdefault.jpg

In fact, once you know the ID of a YouTube video (the ?v= bit in a YouTube URL), you can figure out the path to multiple images of different sizes:

(Although that last one—maxresdefault.jpg—might not work for older videos.)

Okay, so I need to extract the ID from the YouTube URL. Here’s the PHP I use to do that:

parse_str(parse_url($url, PHP_URL_QUERY), $arguments);
$id = $arguments['v'];

Then I can put together some HTML like this:

<div>
<a class="videoimglink" href="'.$url.'">
<img width="100%" loading="lazy"
src="https://i.ytimg.com/vi/'.$id.'/default.jpg"
alt="'.$response['title'].'"
srcset="
https://i.ytimg.com/vi/'.$id.'/mqdefault.jpg 320w,
https://i.ytimg.com/vi/'.$id.'/hqdefault.jpg 480w,
https://i.ytimg.com/vi/'.$id.'/maxresdefault.jpg 1280w
">
</a>
</div>

Now I’ve got a clickable responsive image that links through to the video on YouTube. Time to enhance. I’m going to add a smidgen of JavaScript to listen for a click on that link.

Over on The Session, I’m using addEventListener but here on adactio.com I’m going to be dirty and listen for the event directly in the markup using the onclick attribute.

When the link is clicked, I nuke the link and the image using innerHTML. This injects an iframe where the link used to be (by updating the innerHTML value of the link’s parentNode).

onclick="event.preventDefault();
this.parentNode.innerHTML='<iframe src=https://www.youtube-nocookie.com/embed/'.$id.'?autoplay=1></iframe>'"

But notice that I’m not using the default YouTube URL for the iframe. That would be:

https://www.youtube.com/embed/-eiqhVmSPcs

Instead I’m swapping out the domain youtube.com for youtube-nocookie.com:

https://www.youtube-nocookie.com/embed/-eiqhVmSPcs

I can’t remember where I first came across this undocumented parallel version of YouTube that has, yes, you guessed it, no cookies. It turns out that, not only is the default YouTube embed code bad for performance, it is—unsurprisingly—bad for privacy too. So the youtube-nocookie.com domain can protect your site’s visitors from intrusive tracking. Pass it on.

Anyway, I’ve got the markup I want now:

<div>
<a class="videoimglink" href="https://www.youtube.com/watch?v=-eiqhVmSPcs"
onclick="event.preventDefault();
this.parentNode.innerHTML='<iframe src=https://www.youtube-nocookie.com/embed/-eiqhVmSPcs?autoplay=1></iframe>'">
<img width="100%" loading="lazy"
src="https://i.ytimg.com/vi/-eiqhVmSPcs/default.jpg"
alt="The Banks Of Lough Gowna (jig) on mandolin"
srcset="
https://i.ytimg.com/vi/-eiqhVmSPcs/mqdefault.jpg 320w,
https://i.ytimg.com/vi/-eiqhVmSPcs/hqdefault.jpg 480w,
https://i.ytimg.com/vi/-eiqhVmSPcs/maxresdefault.jpg 1280w
">
</a>
</div>

The functionality is all there. But I want to style the embedded images to look more like playable videos. Time to break out some CSS (this is why I added the videoimglink class to the YouTube link).

.videoimglink {
    display: block;
    position: relative;
}

I’m going to use generated content to create a play button icon. Because I can’t use generated content on an img element, I’m applying these styles to the containing .videoimglink a element.

.videoimglink::before {
    content: '▶';
}

I was going to make an SVG but then I realised I could just be lazy and use the unicode character instead.

Right. Time to draw the rest of the fucking owl:

.videoimglink::before {
    content: '▶';
    display: inline-block;
    position: absolute;
    background-color: var(--background-color);
    color: var(--link-color);
    border-radius: 50%;
    width: 10vmax;
    height: 10vmax;
    top: calc(50% - 5vmax);
    left: calc(50% - 5vmax);
    font-size: 6vmax;
    text-align: center;
    text-indent: 1vmax;
    opacity: 0.5;
}

That’s a bunch of instructions for sizing and positioning. I’d explain it, but that would require me to understand it and frankly, I’m not entirely sure I do. But it works. I think.

With a translucent play icon positioned over the thumbnail, all that’s left is to add a :hover style to adjust the opacity:

.videoimglink:hover::before,
.videoimglink:focus::before {
    opacity: 0.75;
}

Wheresoever thou useth :hover, thou shalt also useth :focus.

Okay. It’s good enough. Ship it!

The Banks Of Lough Gowna (jig) on mandolin

If you embed YouTube videos on your site, and you’d like to make them more performant, check out this custom element that Paul made: Lite YouTube Embed. And here’s a clever technique that uses the srcdoc attribute to get a similar result (but don’t forget to use the youtube-nocookie.com domain).

Utopia

Trys and James recently unveiled their Utopia project. They’ve been tinkering away at it behind the scenes for quite a while now.

You can check out the website and read the blog to get the details of how it accomplishes its goal:

Elegantly scale type and space without breakpoints.

I may well be biased, but I really like this project. I’ve been asking myself why I find it so appealing. Here are a few of the attributes of Utopia that strike a chord with me…

It’s collaborative

Collaboration is at the heart of Clearleft’s work. I know everyone says that, but we’ve definitely seen a direct correlation: projects with high levels of collaboration are invariably more successful than projects where people are siloed.

The genesis for Utopia came about after Trys and James worked together on a few different projects. It’s all too easy to let design and development splinter off into their own caves, but on these projects, Trys and James were working (literally) side by side. This meant that they could easily articulate frustrations to one another, and more important, they could easily share their excitement.

The end result of their collaboration is some very clever code. There’s an irony here. This code could be used to discourage collaboration! After all, why would designers and developers sit down together if they can just pass these numbers back and forth?

But I don’t think that Utopia will appeal to designers and developers who work in that way. Born in the spirit of collaboration, I suspect that it will mostly benefit people who value collaboration.

It’s intrinsic

If you’re a control freak, you may not like Utopia. The idea is that you specify the boundaries of what you’re trying to accomplish—minimum/maximum font sizes, minumum/maximum screen sizes, and some modular scales. Then you let the code—and the browser—do all the work.

On the one hand, this feels like surrending control. But on the other hand, because the underlying system is so robust, it’s a way of guaranteeing quality, even in situations you haven’t accounted for.

If someone asks you, “What size will the body copy be when the viewport is 850 pixels wide?”, your answer would have to be “I don’t know …but I do know that it will be appropriate.”

This feels like a very declarative way of designing. It reminds me of the ethos behind Andy and Heydon’s site, Every Layout. They call it algorithmic layout design:

Employing algorithmic layout design means doing away with @media breakpoints, “magic numbers”, and other hacks, to create context-independent layout components. Your future design systems will be more consistent, terser in code, and more malleable in the hands of your users and their devices.

See how breakpoints are mentioned as being a very top-down approach to layout? Remember the tagline for Utopia, which aims for fluid responsive design?

Elegantly scale type and space without breakpoints.

Unsurprisingly, Andy really likes Utopia:

As the co-author of Every Layout, my head nearly fell off from all of the nodding when reading this because this is the exact sort of approach that we preach: setting some rules and letting the browser do the rest.

Heydon describes this mindset as automating intent. I really like that. I think that’s what Utopia does too.

As Heydon said at Patterns Day:

Be your browser’s mentor, not its micromanager.

The idea is that you give it rules, you give it axioms or principles to work on, and you let it do the calculation. You work with the in-built algorithms of the browser and of CSS itself.

This is all possible thanks to improvements to CSS like calc, flexbox and grid. Jen calls this approach intrinsic web design. Last year, I liveblogged her excellent talk at An Event Apart called Designing Intrinsic Layouts.

Utopia feels like it has the same mindset as algorithmic layout design and intrinsic web design. Trys and James are building on the great work already out there, which brings me to the final property of Utopia that appeals to me…

It’s iterative

There isn’t actually much that’s new in Utopia. It’s a combination of existing techniques. I like that. As I said recently:

I’m a great believer in the HTML design principle, Evolution Not Revolution:

It is better to evolve an existing design rather than throwing it away.

First of all, Utopia uses the idea of modular scales in typography. Tim Brown has been championing this idea for years.

Then there’s the idea of typography being fluid and responsive—just like Jason Pamental has been speaking and writing about.

On the code side, Utopia wouldn’t be possible without the work of Mike Reithmuller and his breakthroughs on responsive and fluid typography, which led to Tim’s work on CSS locks.

Utopia takes these building blocks and combines them. So if you’re wondering if it would be a good tool for one of your projects, you can take an equally iterative approach by asking some questions…

Are you using fluid type?

Do your font-sizes increase in proportion to the width of the viewport? I don’t mean in sudden jumps with @media breakpoints—I mean some kind of relationship between font size and the vw (viewport width) unit. If so, you’re probably using some kind of mechanism to cap the minimum and maximum font sizes—CSS locks.

I’m using that technique on Resilient Web Design. But I’m not changing the relative difference between different sized elements—body copy, headings, etc.—as the screen size changes.

Are you using modular scales?

Does your type system have some kind of ratio that describes the increase in type sizes? You probably have more than one ratio (unlike Resilient Web Design). The ratio for small screens should probably be smaller than the ratio for big screens. But rather than jump from one ratio to another at an arbitrary breakpoint, Utopia allows the ratio to be fluid.

So it’s not just that font sizes are increasing as the screen gets larger; the comparative difference is also subtly changing. That means there’s never a sudden jump in font size at any time.

Are you using custom properties?

A technical detail this, but the magic of Utopia relies on two powerful CSS features: calc() and custom properties. These two workhorses are used by Utopia to generate some CSS that you can stick at the start of your stylesheet. If you ever need to make changes, all the parameters are defined at the top of the code block. Tweak those numbers and watch everything cascade.

You’ll see that there’s one—and only one—media query in there. This is quite clever. Usually with CSS locks, you’d need to have a media query for every different font size in order to cap its growth at the maximum screen size. With Utopia, the maximum screen size—100vw—is abstracted into a variable (a custom property). The media query then changes its value to be the upper end of your CSS lock. So it doesn’t matter how many different font sizes you’re setting: because they all use that custom property, one single media query takes care of capping the growth of every font size declaration.

If you’re already using CSS locks, modular scales, and custom properties, Utopia is almost certainly going to be a good fit for you.

If you’re not yet using those techniques, but you’d like to, I highly recommend using Utopia on your next project.

CSS for all

There have been some great new CSS properties and values shipping in Firefox recently.

Miriam Suzanne explains the difference between the newer revert value and the older inherit, initial and unset values in a video on the Mozilla Developer channel:

display: revert;

In another video, Jen describes some new properties for styling underlines (on links, for example):

text-decoration-thickness:  0.1em;
text-decoration-color: red;
text-underline-offset: 0.2em;
text-decoration-skip-ink: auto;

Great stuff!

As far as I can tell, all of these properties are available to you regardless of whether you are serving your website over HTTP or over HTTPS. That may seem like an odd observation to make, but I invite you to cast your mind back to January 2018. That’s when the Mozilla Security Blog posted about moving to secure contexts everywhere:

Effective immediately, all new features that are web-exposed are to be restricted to secure contexts. Web-exposed means that the feature is observable from a web page or server, whether through JavaScript, CSS, HTTP, media formats, etc. A feature can be anything from an extension of an existing IDL-defined object, a new CSS property, a new HTTP response header, to bigger features such as WebVR.

(emphasis mine)

Buzz Lightyear says to Woody: Secure contexts …secure contexts everywhere!

Despite that “effective immediately” clause, I haven’t observed any of the new CSS properties added in the past two years to be restricted to HTTPS. I’m glad about that. I wrote about this announcement at the time:

I am in total agreement that we should be encouraging everyone to switch to HTTPS. But requiring HTTPS in order to use CSS? The ends don’t justify the means.

If there were valid security reasons for making HTTPS a requirement, I would be all for enforcing this. But these are two totally separate areas. Enforcing HTTPS by withholding CSS support is no different to enforcing AMP by withholding search placement.

There’s no official word from the Mozilla Security Blog about any change to their two-year old “effective immediately” policy, and the original blog post hasn’t been updated. Maybe we can all just pretend it never happened.

Dark mode

I had a very productive time at Indie Web Camp Amsterdam. The format really lends itself to getting the most of a weekend—one day of discussions followed by one day of hands-on making and doing. You should definitely come along to Indie Web Camp Brighton on October 19th and 20th to experience it for yourself.

By the end of the “doing” day, I had something fun to demo—a dark mode for my website.

Y’know, when I first heard about Apple adding dark mode to their OS—and also to CSS—I thought, “Oh, great, Apple are making shit up again!” But then I realised that, like user style sheets, this is one more reminder to designers and developers that they don’t get the last word—users do.

Applying the dark mode styles is pretty straightforward in theory. You put the styles inside this media query:

@media (prefers-color-scheme: dark) {
...
}

Rather than over-riding every instance of a colour in my style sheet, I decided I’d do a little bit of refactoring first and switch to using CSS custom properties (or variables, if you will).

:root {
  --background-color: #fff;
  --text-color: #333;
  --link-color: #b52;
}
body {
  background-color: var(--background-color);
  color: var(--text-color);
}
a {
  color: var(--link-color);
}

Then I can over-ride the custom properties without having to touch the already-declared styles:

@media (prefers-color-scheme: dark) {
  :root {
    --background-color: #111416
    --text-color: #ccc;
    --link-color: #f96;
  }
}

All in all, I have about a dozen custom properties for colours—variations for text, backgrounds, and interface elements like links and buttons.

By using custom properties and the prefers-color-scheme media query, I was 90% of the way there. But the devil is in the details.

I have SVGs of sparklines on my homepage. The SVG has a hard-coded colour value in the stroke attribute of the path element that draws the sparkline. Fortunately, this can be over-ridden in the style sheet:

svg.activity-sparkline path {
  stroke: var(--text-color);
}

The real challenge came with the images I use in the headers of my pages. They’re JPEGs with white corners on one side and white gradients on the other.

header images

I could make them PNGs to get transparency, but the file size would shoot up—they’re photographic images (with a little bit of scan-line treatment) so JPEGs (or WEBPs) are the better format. Then I realised I could use CSS to recreate the two effects:

  1. For the cut-out triangle in the top corner, there’s clip-path.
  2. For the gradient, there’s …gradients!
background-image: linear-gradient(
  to right,
  transparent 50%,
  var(—background-color) 100%
);

Oh, and I noticed that when I applied the clip-path for the corners, it had no effect in Safari. It turns out that after half a decade of support, it still only exists with -webkit prefix. That’s just ridiculous. At this point we should be burning vendor prefixes with fire. I can’t believe that Apple still ships standardised CSS properties that only work with a prefix.

In order to apply the CSS clip-path and gradient, I needed to save out the images again, this time without the effects baked in. I found the original Photoshop file I used to export the images. But I don’t have a copy of Photoshop any more. I haven’t had a copy of Photoshop since Adobe switched to their Mafia model of pricing. A quick bit of searching turned up Photopea, which is pretty much an entire recreation of Photoshop in the browser. I was able to open my old PSD file and re-export my images.

LEGO clone trooper Brighton bandstand Scaffolding Tokyo Florence

Let’s just take a moment here to pause and reflect on the fact that we can now use CSS to create all sorts of effects that previously required a graphic design tool like Photoshop. I could probably do those raster scan lines with CSS if I were smart enough.

dark mode

This is what I demo’d at the end of Indie Web Camp Amsterdam, and I was pleased with the results. But fate had an extra bit of good timing in store for me.

The very next day at the View Source conference, Melanie Richards gave a fantastic talk called The Tailored Web: Effectively Honoring Visual Preferences (seriously, conference organisers, you want this talk on your line-up). It was packed with great insights and advice on impementing dark mode, like this little gem for adjusting images:

@media (prefers-color-scheme: dark) {
  img {
    filter: brightness(.8) contrast(1.2);
  }
}

Melanie also pointed out that you can indicate the presence of dark mode styles to browsers, although the mechanism is yet to shake out. You can do it in CSS:

:root {
  color-scheme: light dark;
}

But you can also do it in HTML:

That allows browsers to swap out replaced content; interface elements like form fields and dropdowns.

Oh, and one other addition I added after the fact was swapping out map imagery by using the picture element to point to darker map tiles:


map

light map dark map

So now I’ve got a dark mode for my website. Admittedly, it’s for just one of the eight style sheets. I’ve decided that, while I’ll update my default styles at every opportunity, I’m going to preservethe other skins as they are, like the historical museum pieces they are.

If you’re on the latest version of iOS, go ahead and toggle the light and dark options in your system preferences to flip between this site’s colour schemes.

Getting started

I got an email recently from a young person looking to get into web development. They wanted to know what languages they should start with, whether they should a Mac or a Windows PC, and what some places to learn from.

I wrote back, saying this about languages:

For web development, start with HTML, then CSS, then JavaScript (and don’t move on to JavaScript too quickly—really get to grips with HTML and CSS first).

And this is what I said about hardware and software:

It doesn’t matter whether you use a Mac or a Windows PC, as long as you’ve got an internet connection, some web browsers (Chrome, Firefox, for example) and a text editor. There are some very good free text editors available for Mac and PC:

For resources, I had a trawl through links I’ve tagged with “learning” and “html” and sent along some links to free online tutorials:

After sending that email, I figured that this list might be useful to anyone else looking to start out in web development. If you know of anyone in that situation, I hope this list might help.

Principle

I like good design principles. I collect design principles—of varying quality—at principles.adactio.com. Ben Brignell also has a (much larger) collection at principles.design.

You can spot the less useful design principles after a while. They tend to be wishy-washy; more like empty aspirational exhortations than genuinely useful guidelines for alignment. I’ve written about what makes for good design principles before. Matthew Ström also asked—and answered—What makes a good design principle?

  • Good design principles are memorable.
  • Good design principles help you say no.
  • Good design principles aren’t truisms.
  • Good design principles are applicable.

I like those. They’re like design principles for design principles.

One set of design principles that I’ve included in my collection is from gov.uk: government design principles . I think they’re very well thought-through (although I’m always suspicious when I see a nice even number like 10 for the amount of items in the list). There’s a great line in design principle number two—Do less:

Government should only do what only government can do.

This wasn’t a theoretical issue. The multiple departmental websites that preceded gov.uk were notorious for having too much irrelevant content—content that was readily available elsewhere. It was downright wasteful to duplicate that content on a government site. It wasn’t appropriate.

Appropriateness is something I keep coming back to when it comes to evaluating web technologies. I don’t think there are good tools and bad tools; just tools that are appropriate or inapropriate for the task at hand. Whether it’s task runners or JavaScript frameworks, appropriateness feels like it should be the deciding factor.

I think that the design principle from GDS could be abstracted into a general technology principle:

Any particular technology should only do what only that particular technology can do.

Take JavaScript, for example. It feels “wrong” when a powerful client-side JavaScript framework is applied to something that could be accomplished using HTML. Making a blog that’s a single page app is over-engineering. It violates this principle:

JavaScript should only do what only JavaScript can do.

Need to manage state or immediately update the interface in response to user action? Only JavaScript can do that. But if you need to present the user with some static content, JavaScript can do that …but it’s not the only technology that can do that. HTML would be more appropriate.

I realise that this is basically a reformulation of one of my favourite design principles, the rule of least power:

Choose the least powerful language suitable for a given purpose.

Or, as Derek put it:

In the web front-end stack — HTML, CSS, JS, and ARIA — if you can solve a problem with a simpler solution lower in the stack, you should. It’s less fragile, more foolproof, and just works.

ARIA should only do what only ARIA can do.

JavaScript should only do what only JavaScript can do.

CSS should only do what only CSS can do.

HTML should only do what only HTML can do.

Inlining SVG background images in CSS with custom properties

Here’s a tiny lesson that I picked up from Trys that I’d like to share with you…

I was working on some upcoming changes to the Clearleft site recently. One particular component needed some SVG background images. I decided I’d inline the SVGs in the CSS to avoid extra network requests. It’s pretty straightforward:

.myComponent {
    background-image: url('data:image/svg+xml;utf8,<svg> ... </svg>');
}

You can basically paste your SVG in there, although you need to a little bit of URL encoding: I found that converting # to %23 to was enough for my needs.

But here’s the thing. My component had some variations. One of the variations had multiple background images. There was a second background image in addition to the first. There’s no way in CSS to add an additional background image without writing a whole background-image declaration:

.myComponent--variant {
    background-image: url('data:image/svg+xml;utf8,<svg> ... </svg>'), url('data:image/svg+xml;utf8,<svg> ... </svg>');
}

So now I’ve got the same SVG source inlined in two places. That negates any performance benefits I was getting from inlining in the first place.

That’s where Trys comes in. He shared a nifty technique he uses in this exact situation: put the SVG source into a custom property!

:root {
    --firstSVG: url('data:image/svg+xml;utf8,<svg> ... </svg>');
    --secondSVG: url('data:image/svg+xml;utf8,<svg> ... </svg>');
}

Then you can reference those in your background-image declarations:

.myComponent {
    background-image: var(--firstSVG);
}
.myComponent--variant {
    background-image: var(--firstSVG), var(--secondSVG);
}

Brilliant! Not only does this remove any duplication of the SVG source, it also makes your CSS nice and readable: no more big blobs of SVG source code in the middle of your style sheet.

You might be wondering what will happen in older browsers that don’t support CSS custom properties (that would be Internet Explorer 11). Those browsers won’t get any background image. Which is fine. It’s a background image. Therefore it’s decoration. If it were an important image, it wouldn’t be in the background.

Progressive enhancement, innit?

Split

When I talk about evaluating technology for front-end development, I like to draw a distinction between two categories of technology.

On the one hand, you’ve got the raw materials of the web: HTML, CSS, and JavaScript. This is what users will ultimately interact with.

On the other hand, you’ve got all the tools and technologies that help you produce the HTML, CSS, and JavaScript: pre-processors, post-processors, transpilers, bundlers, and other build tools.

Personally, I’m much more interested and excited by the materials than I am by the tools. But I think it’s right and proper that other developers are excited by the tools. A good balance of both is probably the healthiest mix.

I’m never sure what to call these two categories. Maybe the materials are the “external” technologies, because they’re what users will interact with. Whereas all the other technologies—that mosty live on a developer’s machine—are the “internal” technologies.

Another nice phrase is something I heard during Chris’s talk at An Event Apart in Seattle, when he quoted Brad, who talked about the front of the front end and the back of the front end.

I’m definitely more of a front-of-the-front-end kind of developer. I have opinions on the quality of the materials that get served up to users; the output should be accessible and performant. But I don’t particularly care about the tools that produced those materials on the back of the front end. Use whatever works for you (or whatever works for your team).

As a user-centred developer, my priority is doing what’s best for end users. That’s not to say I don’t value developer convenience. I do. But I prioritise user needs over developer needs. And in any case, those two needs don’t even come into conflict most of the time. Like I said, from a user’s point of view, it’s irrelevant what text editor or version control system you use.

Now, you could make the argument that anything that is good for developer convenience is automatically good for user experience because faster, more efficient development should result in better output. While that’s true in theory, I highly recommend Alex’s post, The “Developer Experience” Bait-and-Switch.

Where it gets interesting is when a technology that’s designed for developer convenience is made out of the very materials being delivered to users. For example, a CSS framework like Bootstrap is made of CSS. That’s different to a tool like Sass which outputs CSS. Whether or not a developer chooses to use Sass is irrelevant to the user—the final output will be CSS either way. But if a developer chooses to use a CSS framework, that decision has a direct impact on the user experience. The user must download the framework in order for the developer to get the benefit.

So whereas Sass sits at the back of the front end—where I don’t care what you use—Bootstrap sits at the front of the front end. For tools like that, I don’t think saying “use whatever works for you” is good enough. It’s got to be weighed against the cost to the user.

Historically, it’s been a similar story with JavaScript libraries. They’re written in JavaScript, and so they’re going to be executed in the browser. If a developer wanted to use jQuery to make their life easier, the user paid the price in downloading the jQuery library.

But I’ve noticed a welcome change with some of the bigger JavaScript frameworks. Whereas the initial messaging around frameworks like React touted the benefits of state management and the virtual DOM, I feel like that’s not as prevalent now. You’re much more likely to hear people—quite rightly—talk about the benefits of modularity and componentisation. If you combine that with the rise of Node—which means that JavaScript is no longer confined to the browser—then these frameworks can move from the front of the front end to the back of the front end.

We’ve certainly seen that at Clearleft. We’ve worked on multiple React projects, but in every case, the output was server-rendered. Developers get the benefit of working with a tool that helps them. Users don’t pay the price.

For me, this question of whether a framework will be used on the client side or the server side is crucial.

Let me tell you about a Clearleft project that sticks in my mind. We were working with a big international client on a product that was going to be rolled out to students and teachers in developing countries. This was right up my alley! We did plenty of research into network conditions and typical device usage. That then informed a tight performance budget. Every design decision—from web fonts to images—was informed by that performance budget. We were producing lean, mean markup, CSS, and JavaScript. But we weren’t the ones implementing the final site. That was being done by the client’s offshore software team, and they insisted on using React. “That’s okay”, I thought. “React can be used server-side so we can still output just what’s needed, right?” Alas, no. These developers did everything client side. When the final site launched, the log-in screen alone required megabytes of JavaScript just to render a form. It was, in my opinion, entirely unfit for purpose. It still pains me when I think about it.

That was a few years ago. I think that these days it has become a lot easier to make the decision to use a framework on the back of the front end. Like I said, that’s certainly been the case on recent Clearleft projects that involved React or Vue.

It surprises me, then, when I see the question of server rendering or client rendering treated almost like an implementation detail. It might be an implementation detail from a developer’s perspective, but it’s a key decision for the user experience. The performance cost of putting your entire tech stack into the browser can be enormous.

Alex Sanders from the development team at The Guardian published a post recently called Revisiting the rendering tier . In it, he describes how they’re moving to React. Now, if this were a move to client-rendered React, that would make a big impact on the user experience. The thing is, I couldn’t tell from the article whether React was going to be used in the browser or on the server. The article talks about “rendering”—which is something that browsers do—and “the DOM”—which is something that only exists in browsers.

So I asked. It turns out that this plan is very much about generating HTML and CSS on the server before sending it to the browser. Excellent!

With that question answered, I’m cool with whatever they choose to use. In this case, they’re choosing to use CSS-in-JS (although, to be pedantic, there’s no C anymore so technically it’s SS-in-JS). As long as the “JS” part is JavaScript on a server, then it makes no difference to the end user, and therefore no difference to me. Not my circus, not my monkeys. For users, the end result is the same whether styling is applied via a selector in an external stylesheet or, for example, via an inline style declaration (and in some situations, a server-rendered CSS-in-JS solution might be better for performance). And so, as a user-centred developer, this is something that I don’t need to care about.

Except…

I have misgivings. But just to be clear, these misgivings have nothing to do with users. My misgivings are entirely to do with another group of people: the people who make websites.

There’s a second-order effect. By making React—or even JavaScript in general—a requirement for styling something on a web page, the barrier to entry is raised.

At least, I think that the barrier to entry is raised. I completely acknowledge that this is a subjective judgement. In fact, the reason why a team might decide to make JavaScript a requirement for participation might well be because they believe it makes it easier for people to participate. Let me explain…

It wasn’t that long ago that devs coming from a Computer Science background were deriding CSS for its simplicity, complaining that “it’s broken” and turning their noses up at it. That rhetoric, thankfully, is waning. Nowadays they’re far more likely to acknowledge that CSS might be simple, but it isn’t easy. Concepts like the cascade and specificity are real head-scratchers, and any prior knowledge from imperative programming languages won’t help you in this declarative world—all your hard-won experience and know-how isn’t fungible. Instead, it seems as though all this cascading and specificity is butchering the modularity of your nicely isolated components.

It’s no surprise that programmers with this kind of background would treat CSS as damage and find ways to route around it. The many flavours of CSS-in-JS are testament to this. From a programmer’s point of view, this solution has made things easier. Best of all, as long as it’s being done on the server, there’s no penalty for end users. But now the price is paid in the diversity of your team. In order to participate, a Computer Science programming mindset is now pretty much a requirement. For someone coming from a more declarative background—with really good HTML and CSS skills—everything suddenly seems needlessly complex. And as Tantek observed:

Complexity reinforces privilege.

The result is a form of gatekeeping. I don’t think it’s intentional. I don’t think it’s malicious. It’s being done with the best of intentions, in pursuit of efficiency and productivity. But these code decisions are reflected in hiring practices that exclude people with different but equally valuable skills and perspectives.

Rachel describes HTML, CSS and our vanishing industry entry points:

If we make it so that you have to understand programming to even start, then we take something open and enabling, and place it back in the hands of those who are already privileged.

I think there’s a comparison here with toxic masculinity. Toxic masculinity is obviously terrible for women, but it’s also really shitty for men in the way it stigmatises any male behaviour that doesn’t fit its worldview. Likewise, if the only people your team is interested in hiring are traditional programmers, then those programmers are going to resent having to spend their time dealing with semantic markup, accessibility, styling, and other disciplines that they never trained in. Heydon correctly identifies this as reluctant gatekeeping:

By assuming the role of the Full Stack Developer (which is, in practice, a computer scientist who also writes HTML and CSS), one takes responsibility for all the code, in spite of its radical variance in syntax and purpose, and becomes the gatekeeper of at least some kinds of code one simply doesn’t care about writing well.

This hurts everyone. It’s bad for your team. It’s even worse for the wider development community.

Last year, I was asked “Is there a fear or professional challenge that keeps you up at night?” I responded:

My greatest fear for the web is that it becomes the domain of an elite priesthood of developers. I firmly believe that, as Tim Berners-Lee put it, “this is for everyone.” And I don’t just mean it’s for everyone to use—I believe it’s for everyone to make as well. That’s why I get very worried by anything that raises the barrier to entry to web design and web development.

I’ve described a number of dichotomies here:

  • Materials vs. tools,
  • Front of the front end vs. back of the front end,
  • User experience vs. developer experience,
  • Client-side rendering vs. server-side rendering,
  • Declarative languages vs. imperative languages.

But the split that worries the most is this:

  • The people who make the web vs. the people who are excluded from making the web.

Drag’n’drop revisited

I got a message from a screen-reader user of The Session recently, letting me know of a problem they were having. I love getting any kind of feedback around accessibility, so this was like gold dust to me.

They pointed out that the drag’n’drop interface for rearranging the order of tunes in a set was inaccessible.

Drag and drop

Of course! I slapped my forehead. How could I have missed this?

It had been a while since I had implemented that functionality, so before even looking at the existing code, I started to think about how I could improve the situation. Maybe I could capture keystroke events from the arrow keys and announce changes via ARIA values? That sounded a bit heavy-handed though: mess with people’s native keyboard functionality at your peril.

Then I looked at the code. That was when I realised that the fix was going to be much, much easier than I thought.

I documented my process of adding the drag’n’drop functionality back in 2016. Past me had his progressive enhancement hat on:

One of the interfaces needed for this feature was a form to re-order items in a list. So I thought to myself, “what’s the simplest technology to enable this functionality?” I came up with a series of select elements within a form.

Reordering

The problem was in my feature detection:

There’s a little bit of mustard-cutting going on: does the dragula object exist, and does the browser understand querySelector? If so, the select elements are hidden and the drag’n’drop is enabled.

The logic was fine, but the execution was flawed. I was being lazy and hiding the select elements with display: none. That hides them visually, but it also hides them from screen readers. I swapped out that style declaration for one that visually hides the elements, but keeps them accessible and focusable.

It was a very quick fix. I had the odd sensation of wanting to thank Past Me for making things easy for Present Me. But I don’t want to talk about time travel because if we start talking about it then we’re going to be here all day talking about it, making diagrams with straws.

I pushed the fix, told the screen-reader user who originally contacted me, and got a reply back saying that everything was working great now. Success!

CSS custom properties in generated content

Cassie posted a neat tiny lesson that she’s written a reduced test case for.

Here’s the situation…

CSS custom properties are fantastic. You can drop them in just about anywhere that a property takes a value.

Here’s an example of defining a custom property for a length:

:root {
    --my-value: 1em;
}

Then I can use that anywhere I’d normally give something a length:

.my-element {
    margin-bottom: var(--my-value);
}

I went a bit overboard with custom properties on the new Patterns Day site. I used them for colour values, font stacks, and spacing. Design tokens, I guess. They really come into their own when you combine them with media queries: you can update the values of the custom properties based on screen size …without having to redefine where those properties are applied. Also, they can be updated via JavaScript so they make for a great common language between CSS and JavaScript: you can define where they’re used in your CSS and then update their values in JavaScript, perhaps in response to user interaction.

But there are a few places where you can’t use custom properties. You can’t, for example, use them as part of a media query. This won’t work:

@media all and (min-width: var(--my-value)) {
    ...
}

You also can’t use them in generated content if the value is a number. This won’t work:

:root {
    --number-value: 15;
}
.my-element::before {
    content: var(--number-value);
}

Fair enough. Generated content in CSS is kind of a strange beast. Eric delivered an entire hour-long talk at An Event Apart in Seattle on generated content.

But Cassie found a workaround if the value you want to put into that content property is numeric. The CSS counter value is a kind of generated content—the numbers that appear in front of ordered list items. And you can control the value of those numbers from CSS.

CSS counters work kind of like variables. You name them and assign values to them using the counter-reset property:

.my-element {
    counter-reset: mycounter 15;
}

You can then reference the value of mycounter in a content property using the counter value:

.my-element {
    content: counter(mycounter);
}

Cassie realised that even though you can’t pass in a custom property directly to generated content, you can pass in a custom property to the counter-reset property. So you can do this:

:root {
    --number-value: 15;
}
.my-element {
    counter-reset: mycounter var(--number-value);
    content: counter(mycounter);
}

In a roundabout way, this allows you to use a custom property for generated content!

I realise that the use cases are pretty narrow, but I can’t help but be impressed with the thinking behind this. Personally, I would’ve just read that generated content doesn’t accept custom properties and moved on. I would’ve given up quickly. But Cassie took a step back and found a creative pass-the-parcel solution to the problem.

I feel like this is a hack in the best sense of the word: a creatively improvised solution to a problem or limitation.

I was trying to display the numeric value stored in a CSS variable inside generated content… Turns out you can’t do that. But you can do this… codepen.io/cassie-codes/p… (not saying you should, but you could)

Move Fast and Don’t Break Things by Scott Jehl

Scott Jehl is speaking at An Event Apart in Seattle—yay! His talk is called Move Fast and Don’t Break Things:

Performance is a high priority for any site of scale today, but it can be easier to make a site fast than to keep it that way. As a site’s features and design evolves, its performance is often threatened for a number of reasons, making it hard to ensure fast, resilient access to services. In this session, Scott will draw from real-world examples where business goals and other priorities have conflicted with page performance, and share some strategies and practices that have helped major sites overcome those challenges to defend their speed without compromises.

The title is a riff on the “move fast and break things” motto, which comes from a more naive time on the web. But Scott finds part of it relatable. Things break. We want to move fast without breaking things.

This is a performance talk, which is another kind of moving fast. Scott starts with a brief history of not breaking websites. He’s been chipping away at websites for 20 years now. Remember Positioning Is Everything? How about Quirksmode? That one's still around.

In the early days, building a website that was "not broken" was difficult, but it was difficult for different reasons. We were focused on consistency. We had deal with differences between browsers. There were two ways of dealing with browsers: browser detection and feature detection.

The feature-based approach was more sustainable but harder. It fits nicely with the practice of progressive enhancement. It's a good mindset for dealing with the explosion of devices that kicked off later. Touch screens made us rethink our mouse and hover-centric matters. That made us realise how much keyboard-driven access mattered all along.

Browsers exploded too. And our data networks changed. With this explosion of considerations, it was clear that our early ideas of “not broken” didn’t work. Our notion of what constituted “not broken” was itself broken. Consistency just doesn’t cut it.

But there was a comforting part to this too. It turned out that progressive enhancement was there to help …even though we didn’t know what new devices were going to appear. This is a recurring theme throughout Scott’s career. So given all these benefits of progressive enhancement, it shouldn’t be surprising that it turns out to be really good for performance too. If you practice progressive enhancement, you’re kind of a performance expert already.

People started talking about new performance metrics that we should care about. We’ve got new tools, like Page Speed Insights. It gives tangible advice on how to test things. Web Page Test is another great tool. Once you prove you’re a human, Web Page Test will give you loads of details on how a page loaded. And you get this great visual timeline.

This is where we can start to discuss the metrics we want to focus on. Traditionally, we focused on file size, which still matters. But for goal-setting, we want to focus on user-perceived metrics.

First Meaningful Content. It’s about how soon appears to be useful to a user. Progressive enhancement is a perfect match for this! When you first make request to a website, it’s usually for a web page. But to render that page, it might need to request more files like CSS or JavaScript. All of this adds up. From a user perspective, if the HTML is downloaded, but the browser can’t render it, that’s broken.

The average time for this on the web right now is around six seconds. That’s broken. The render blockers are the problem here.

Consider assets like scripts. Can you get the browser to load them without holding up the rendering of the page? If you can add async or defer to a script element in the head, you should do that. Sometimes that’s not an option though.

For CSS, it’s tricky. We’ve delivered the HTML that we need but we’ve got to wait for the CSS before rendering it. So what can you bundle into that initial payload?

You can user server push. This is a new technology that comes with HTTP2. H2, as it’s called, is very performance-focused. Just turning on H2 will probably make your site faster. Server push allows the server to send files to the browser before the browser has even asked for them. You can do this with directives in Apache, for example. You could push CSS whenever an HTML file is requested. But we need to be careful not to go too far. You don’t want to send too much.

Server push is great in moderation. But it is new, and it may not even be supported by your server.

Another option is to inline CSS (well, actually Scott, this is technically embedding CSS). It’s great for first render, but isn’t it wasteful for caching? Scott has a clever pattern that uses the Cache API to grab the contents of the inlined CSS and put a copy of its contents into the cache. Then it’s ready to be served up by a service worker.

By the way, this isn’t just for CSS. You could grab the contents of inlined SVGs and create cached versions for later use.

So inlining CSS is good, but again, in moderation. You don’t want to embed anything bigger than 15 or 20 kilobytes. You might want separate out the critical CSS and only embed that on first render. You don’t need to go through your CSS by hand to figure out what’s critical—there are tools that to do this that integrate with your build process. Embed that critical CSS into the head of your document, and also start preloading the full CSS. Here’s a clever technique that turns a preload link into a stylesheet link:

<link rel="preload" href="site.css" as="style" onload="this.rel='stylesheet'">

Also include this:

<noscript><link rel="stylesheet" href="site.css"></noscript>

You can also optimise for return visits. It’s all about the cache.

In the past, we might’ve used a cookie to distinguish a returning visitor from a first-time visitor. But cookies kind of suck. Here’s something that Scott has been thinking about: service workers can intercept outgoing requests. A service worker could send a header that matches the current build of CSS. On the server, we can check for this header. If it’s not the latest CSS, we can server push the latest version, or inline it.

The neat thing about service workers is that they have to install before they take over. Scott makes use of this install event to put your important assets into a cache. Only once that is done to we start adding that extra header to requests.

Watch out for an article on the Filament Group blog on this technique!

With performance, more weight doesn’t have to mean more wait. You can have a heavy page that still appears to load quickly by altering the prioritisation of what loads first.

Web pages are very heavy now. There’s a real cost to every byte. Tim’s WhatDoesMySiteCost.com shows that the CNN home page costs almost fifty cents to load for someone in America!

Time to interactive. This is is the time before a user can use what’s on the screen. The issue is almost always with JavaScript. The page looks usable, but you can’t use it yet.

Addy Osmani suggests we should get to interactive in under five seconds on a 3G network on a median mobile device. Your iPhone is not a median mobile device. A typical phone takes six seconds to process a megabyte of JavaScript after it has downloaded. So even if the network is fast, the time to interactive can still be very long.

This all comes down to our industry’s increasing reliance on JavaScript just to render content. There seems to be pendulum shifts between client-side and server-side rendering. It’s been great to see libraries like Vue and Ember embrace server-side rendering.

But even with server-side rendering, there’s still usually a rehydration step where all the JavaScript gets parsed and that really affects time to interaction.

Code splitting can help. Webpack can do this. That helps with first-party JavaScript, but what about third-party JavaScript?

Scott believes easier to make a fast website than to keep a fast website. And that’s down to all the third-party scripts that people throw in: analytics, ads, tracking. They can wreak havoc on all your hard work.

These scripts apparently contribute to the business model, so it can be hard for us to make the case for removing them. Tools like SpeedCurve can help people stay informed on the impact of these scripts. It allows you to set up performance budgets and it shows you when pages go over budget. When that happens, we have leverage to step in and push back.

Assuming you lose that battle, what else can we do?

These days, lots of A/B testing and personalisation happens on the client side. The tooling is easy to use. But they are costly!

A typical problematic pattern is this: the server sends one version of the page, and once the page is loaded, the whole page gets replaced with a different layout targeted at the user. This leads to a terrifying new metric that Scott calls Second Meaningful Content.

Assuming we can’t remove the madness, what can we do? We could at least not do this for first-time visits. We could load the scripts asyncronously. We can preload the scripts at the top of the page. But ideally we want to move these things to the server. Server-side A/B testing and personalisation have existed for a while now.

Scott has been experimenting with a middleware solution. There’s this idea of server workers that Cloudflare is offering. You can manipulate the page that gets sent from the server to the browser—all the things you would do for an A/B test. Scott is doing this by using comments in the HTML to demarcate which portions of the page should be filtered for testing. The server worker then deletes a block for some users, and deletes a different block for other users. Scott has written about this approach.

The point here isn’t about using Cloudflare. The broader point is that it’s much faster to do these things on the server. We need to defend our user’s time.

Another issue, other than third-party scripts, is the page weight on home pages and landing pages. Marketing teams love to fill these things with enticing rich imagery and carousels. They’re really difficult to keep performant because they change all the time. Sometimes we’re not even in control of the source code of these pages.

We can advocate for new best practices like responsive images. The srcset attribute on the img element; the picture element for when you need more control. These are great tools. What’s not so great is writing the markup. It’s confusing! Ideally we’d have a CMS drive this, but a lot of the time, landing pages fall outside of the purview of the CMS.

Scott has been using Vue.js to make a responsive image builder—a form that people can paste their URLs into, which spits out the markup to use. Anything we can do by creating tools like these really helps to defend the performance of a site.

Another thing we can do is lazy loading. Focus on the assets. The BBC homepage uses some lazy loading for images—they blink into view as your scroll down the page. They use LazySizes, which you can find on Github. You use data- attributes to list your image sources. Scott realises that LazySizes is not progressive enhancement. He wouldn’t recommend using it on all images, just some images further down the page.

But thankfully, we won’t need these workarounds soon. Soon we’ll have lazy loading in browsers. There’s a lazyload attribute that we’ll be able to set on img and iframe elements:

<img src=".." alt="..." lazyload="on">

It’s not implemented yet, but it’s coming in Chrome. It might be that this behaviour even becomes the default way of loading images in browsers.

If you dig under the hood of the implementation coming in Chrome, it actually loads all the images, but the ones being lazyloaded are only sent partially with a 206 response header. That gives enough information for the browser to lay out the page without loading the whole image initially.

To wrap up, Scott takes comfort from the fact that there are resilient patterns out there to help us. And remember, it is our job to defend the user’s experience.

How to Think Like a Front-End Developer by Chris Coyier

Alright! It’s day two of An Event Apart in Seattle. The first speaker of the day is Chris Coyier. His talk is called How to Think Like a Front-End Developer. From the website:

The job title “front-end developer” is very real: job boards around the world confirm that. But what is that job, exactly? What do you need to know to do it? You might think those answers are pretty cut and dried, but they’re anything but; front-end development is going through something of an identity crisis. In this engaging talk, Chris will explore this identity through the lens of someone who has self-identified as a front-end developer for a few decades, but more interestingly, through many conversations he’s had with other successful front-end developers. You’ll see just how differently this job can be done and how differently people and companies can think of this role—not just for the sake of doing so, but because you’ll learn to be better at your own jobs by understanding how other people are good at theirs.

I’m going to see if I can keep up with Chris’s frenetic pace…

Chris has his own thoughts about what front-end dev is but he wants to share other ideas too. First of all, some grammar:

I work as a front-end developer.

I work on the front end.

Those are correct. These are not:

I work as a front end developer.

I work on the front-end.

And this is just not a word:

Frontend.

Lots of people are hiring front-end developers. So it’s definitely a job and a common job title. But what does it mean. Chris and Dave talked to eight different people on their Shop Talk Show podcast. Some highlights:

Eric feels that the term “front-end developer” is newer than the CSS Zen Garden. Everyone was a webmaster, or as we’d say now, a full-stack developer. But if someone back then used the term “front-end developer”, he’d know what it meant.

Mina says it deals with things you can see. If it’s a user-facing interface, that’s front-end development.

Trent says that he thinks of himself as a web designer and web builder. He doesn’t feel he has the deep expertise of a developer, and yet he spends all of his time in the browser.

So our job is in the browser. You deal with the browser (moreso than other roles). And by the way, there are a lot of browsers out there.

Maybe the user is what differentiates front-end work. Monica says that a back-end developer is allowed not to care about the user if their job is putting a database together. It’s totally fine not to call yourself a front-end developer, but if you do, you need to care about the user.

There are tons of different devices and browsers. It’s overwhelming. So we just gave up.

So, a front-end developer:

  • Is a job and a job title.
  • It deals with browsers, devices, and users.
  • But what skills does it involve?

It’s taken for granted that you can use a computer. There’s also the soft skills of interacting with co-workers. Then there are the language-specific core skills. Finally, there are the bonus skills—all the stuff that makes you you.

Core skills

The languages you need to strongly understand to read, write and maintain them.

HTML and CSS. Definitely. You don’t come across front-end developers who don’t do those languages. But what about JavaScript?

Eric says it’s fine if you know lots of JavaScript but it’s also fine if you don’t write everything from scratch. But you can’t be oblivious to it. You need to understand what it can do.

So let’s put JavaScript into the bucket of core skills too.

Peggy believes that as a front-end developer you need to have a basic proficiency in accessibility too. This is, after all, about user-facing interfaces.

Bonus skills

The Figma team have a somewhat over-engineered graphic of all the skillsets that people might have, between “baseline” and “supplementary”.

Perhaps we all share a common trunk of skills, and then we branch in different directions.

Right now though, it feels like front-end development is having an identity crisis. It’s all about JavaScript, which is eating the planet.

JavaScript

JavaScript is crazy popular now. It’s unignorable. Yes, it’s the language in the browser, but now it’s also the language in loads of other places too.

Steven Davis says maybe we need to fork the term front-end development. Maybe we need to have UX engineers and JavaScript engineers. Can one person be great at both? Maybe the trunk of skills forks in two very different directions.

Vernon Joyce called this an identity crisis. The concepts in JavaScript frameworks are very alien to people with a background in HTML, CSS, and basic interactive JavaScript.

You could imagine two people called front-end developers meeting, and having nothing in common to talk about. Maybe sports.

Brad says he doesn’t want to be configuring build tools. He thinks of himself as being at the front of front-end development, whereas other people are at the back of front-end development.

This divide is super frustrating to people right now.

Hiring

Michael Schnarnagl brings up the point about how it’s affecting hiring. Back-end developers are being replaced with JavaScript engineers. Lots of things that used to be back-end tasks are now happening on the client side. Component-driven design, site-level architecture, routing, getting data from the back end, mutating data, talking to APIs, and managing state—all of those things are now largely a front-end concern.

Let’s look at CodePen. There’s a little heart icon on each pen. It’s an icon component. And the combination of the heart and the overall count is also a component. And the bar of items altogether—that’s also a component. And the pen it sits under is a component. And the page it’s in is a component. And the URL for that page is a component. Now the whole site is a front-end developer’s concern.

In the past, a front-end developer would ask a back-end developer for an API endpoint. Now with GraphQL, the front-end developer can craft a query to get exactly what they need. Sure, the GraphQL stuff had to be set up in the first place, but that’s one-time task. Once it’s set up, the front-end developer has everything they need.

All the old work hasn’t gone away either. Semantics, accessibility, styling—that’s still the work of a front-end developer as well as all of the new stuff listed above.

Hiring is a big part of this. Lara Schenk talks about going for an interview where she met 90% of the skills listed. Then in an interview, she was asked to do a fizzbuzz test. That’s not the way that Lara thinks. She would’ve been great for that job, but this single task derailed her. She wrote about it, and got snarky comments from people who thought she should’ve been able to do the task. But Lara’s main point was the mismatch between what was advertised and what was actually being hired for.

You see a job posting for front-end developer. Who is that for? Is it for someone into React, webpack, and GraphQL? Or is it for someone into SVG, interaction design, and accessibility? They’re both front-end developers. And remember, they can learn one another’s skills, but when it comes to hiring, it has to be about the skills people have right now.

Peggy talks about how specialised your work can be. You can specialise in SVG. You can specialise in APIs and data.

We’re probably not going to solve this right now. The hiring part is definitely the worst part right now. One solution is to use plain language in job posts. Make it clear what you’re looking for right now and explain what background you’re coming from. Use words instead of a laundry list of requirements.

Heydon Pickering talks about full-stack developers. Their core skills are hardcore computer science skills.

Brad Frost concurs. It tends not to be the other way around. The output tends to be the badly-sketched front of the horse.

Even if there is a divide, that doesn’t absolve any of us from doing a good job. That’s true whether it’s computer science tasks or markup and CSS.

Despite the divide, performance, accessibility, and user experience are all our jobs.

Maybe this term “front-end developer” needs rethinking.

The brain game

Let’s peak into the minds of very different front-end developers. Chris and Dave went to Dribbble, pulled up a bunch of designs and put them in front of their guests on the Shop Talk Show.

Here’s a design of a page.

  • Brad looks at the design and sees a lot of components of different sizes and complexity.
  • Mina sees a bunch of media objects.
  • Eric sees HTML structures. That’s a heading. That’s a list. Over there is an unordered list.
  • Sam sees a lot of typography. She sees a type system.
  • Trent immediately starts thinking about how the design is supposed to work in different screen sizes.

Here’s a different, more image-heavy design.

  • Mina would love to tackle the animations.
  • Trent sees interesting textures and noise. He wonders how he could achieve those effects without exporting giant image files.
  • Brad, unsurprisingly, sees components, even in a seemingly bespoke layout.
  • Eric immediately sees a lot of SVG.
  • Sam needs to know what the HTML is.

Here’s a more geometric design.

  • Sam is drawn to the typography.
  • Mina sees an opportunity to use writing modes.
  • Trent sees a design that would reflow and reshape itself well.
  • Eric sees something with writing mode, grid, and custom fonts.

Here’s a financial mobile UI.

  • Trent wants to run it through a colour-contrast analyser, and he wants to know if the font size is too small.

Here’s a crazy festival website.

  • Mina wonders if it needs a background video, but worries about the performance.

Here’s an on-trend mobile design.

  • Monica sees something that looks like every other website.
  • Ben wonders whether it will work in other parts of the world. How will the interactions work? Separate pages or transitions? How will it feel?

Here’s an image-heavy design.

  • Monica wonders about the priority of which images to load first.

Here’s an extreme navigation with big images.

  • Ben worries about the performance on slow connections.
  • Monica gets stressed out about how much happens when you just click on a link.
  • Peggy sees something static and imagines using Gatsby for it.

Here’s a design that’s map-based.

  • Ben worries about the size of the touch targets.
  • Monica sees an opportunity to use SVGs.

Here’s a card UI.

  • Ben wonders what the browser support is. Can we use CSS grid or do we have to use something older?
  • Monica worries that this needs drag’n’drop. Now you’ve got a nightmare scenario.

Chris has been thinking about and writing about this topic of what makes someone a front-end developer, and what makes someone a good front-end developer. The debate will continue…

Designing Intrinsic Layouts by Jen Simmons

Alright, it’s time for the final talk of day one of An Event Apart in Seattle. The trifecta of CSS talks is going to finish with Jen Simmons talking about Designing Intrinsic Layouts. Here’s the description:

Twenty-five years after the web began, we finally have a real toolkit for creating layouts. Combining CSS Grid, Flexbox, Multicolumn, Flow layout and Writing Modes gives us the technical ability to build layouts today without the horrible hacks and compromises of the past. But what does this mean for our design medium? How might we better leverage the art of graphic design? How will we create something practical, useable, and realistically doable?

In a talk full of specific examples, Jen will walk you through the thinking process of creating accessible & reusable page and component layouts. For the last four years, Jen’s been getting audiences excited about what, when, and why. Now it’s time for how.

I’m not sure if live-blogging is going to work given the visual nature of this talk, but I’ll give it a try…

How many of us have written CSS using display: grid? Quite a few. How many people feel they have a good grip on it? Not so many.

Jen has spent the last few years encouraging people to really push the boundaries of graphic design on the web now that we have the tools to do so in CSS. But Jen is not here today to talk about amazing new things. Instead she’s going to show the “how?” The code is on labs.jensimmons.com.

Let’s look at laying out a header. You might have a header element with a logo image, the site name in an h1, and a nav element with the navigation. The logo, the site name, and the navigation are direct children of the parent header. By default we get everything stacked vertically.

<header role="banner">
    <img class="logo" src="..." alt="...">
    <h1>Site title</h1>
    <nav>
        <ul>
            <li><a href="...">Home</a></li>
            <li><a href="...">Episodes</a></li>
            <li><a href="...">Guests</a></li>
            <li><a href="...">Subscribe</a></li>
            <li><a href="...">About</a></li>
        </ul>
    </nav>
</header>

Why should we care about starting with semantic HTML? It matters for reusability and accessibility, but also for reader modes in browsers. These tools remove the cruft. If you mark up your content well, it will play nicely with reader modes. Interestingly, there are no metrics around how many people are using reader modes (by design). Mozilla has a product called Pocket that’s a “read later” app. It can also turn saved articles into a podcast for you. Well marked up content matters for audio playback.

Now let’s start applying some CSS. Fonts, colours, stuff like that. Everything is still stacking vertically though. It’s flow content. This can be our fallback layout. Now let’s apply our own layout. We could use float: left on the logo. Now we need some margins. We can try applying widths and floats to the h1 and the nav. Now we need a clearfix to get the parent to stretch to the full height of the content. It’s hacky. floats suck. But it’s all we had until we got flexbox. But even using flexbox for this kind of layout is a hack too. What we really need is CSS grid.

Apply display: grid to the header. Use Firefox’s dev tools to inspect the grid. Seeing the grid helps in understanding what’s going on. We’ve got three grid items in three separate rows. Notice that we don’t have margin collapsing any more. We can get rid of margins and use grid-gap instead. But we want is three columns, not three rows. We’ll try:

grid-template-columns: 1fr 1fr 1fr;

Looks okay. Not exactly the spacing we want though. We want the logo and the navigation to take up less space than the site name. We could translate our old percentage values into fr equivalents. 8% becomes 8fr. 75% becomes 75fr. 17% becomes 17fr. But the logo and the nav never shrink below their actual size. Layout isn’t working like we’re used to. The content will never get smaller than the minimum content size. So the amount of space assigned to each column is no longer linear.

Let’s change those fr units to percentages. Now we need to get rid of our gaps. But now when the layout gets small, everything squishes up. This is what we need breakpoints for. But now we can do something else. Let’s make the logo max-content. That column will now be the size of the logo. The other columns can remain `fr:

header {
    grid-template columns: max-content 3fr 1fr;
}

Let’s also define the last one—the navigation—as max-content. We can toss auto in for the middle content (the site name):

header {
    grid-template columns: max-content auto max-content;    }

Let’s layout the navigation horizontally. The best tool for this is flexbox. The li elements are the flex items. So the ul needs to be the flex container.

ul {
    display: flex;
}

Looking good. Let’s allow items to wrap onto another line:

ul {
    display: flex;
    flex-wrap: wrap;
}

Let’s change that navigation from max-content to auto so that it doesn’t get too long:

header {
    grid-template columns: max-content auto auto;   }

(How you want the navigation items to wrap determines whether you use flexbox or grid. Both are perfectly valid choices. There’s nothing wrong with using grid for the small stuff.)

Just look at how little code we need for this layout!

Let’s try a different layout. We’ll put the navigation on a new row.

header {
    grid-template-columns: min-content auto;
    grid-template-rows: auto auto
}

Let’s get the logo to span across both rows:

.logo {
    row-span: 2;
}

Need to finesse the alignment of the navigation? No problem. Play with align-self property on the nav element.

Again, look at how little code this is!

But these layouts are safe. We need to break out of our habits. What about disjointed text? Let’s take the h1. Apply some typography and colour. Also apply overflow-wrap: anywhere. Now the text can break within words.

We can take this further. But to do that, we have to wrap all of my letters in separate spans. Yuck!

Apply display: grid to the h1 that contains all those span children. Say grid-template-columns: repeat(8, 1fr) to make an eight-column repeating grid.

Let’s make it more interesting. We can target each individual letter with grid-column and grid-row. There are many ways to tell the browser where to place grid items. We can tell them the start lines. By default it will take up one cell.

Let’s add some images. Let’s rotate items. Place items wherever we want them. Mess around with the units to see what happens. Play with opacity when elements overlap. See the possibilities!

But, people cry, what about Internet Explorer? Use @supports

/* code for every browser */

@supports (display: grid) {
    /* code for modern browsers */
}

Set up a fallback outside the @supports block. Toggle grid on and enough in dev tools to see how the fallback will look. If this kind of thinking is new to you, please watch youtube.com/layoutland where Jen talks about resilient CSS.

Let’s try something else. Jen got an email announcement for an event. It had an interesting bit of layout with some text overlapping an image.

Mark up the content: some headings and images. By default the images are displayed inline. The headings are displayed as blocks.

Think about where your grid lines will need to go. How many lines will you need? How about setting your columns with 1fr 3fr 3fr 1fr? Now how many rows do you need? You define and the grid on the container and tell the items where to go. Again, it’s not much code. Tweak it. How about setting the columns to be 1fr minmax(100px, 400px) min-content? You have to mess around to see what’s possible. You can use all sorts of units for columns: fixed lengths (pixels, ems, rems), min-content, max-content, percentages, fr units, minmax(), and auto. Play around with the combinations.

Jen shows a whole bunch of her demos. Check them out. Use web inspector to play around with them.

And with that, the first day of An Event Apart Seattle is done!

Making Things Better: Redefining the Technical Possibilities of CSS by Rachel Andrew

The CSStastic afternoon of day one of An Event Apart in Seattle continues with Rachel Andrew. Her talk is Making Things Better: Redefining the Technical Possibilities of CSS. The description reads:

For years we’ve explained that the web is not like print; that a particular idea is not how things work on the web; that certain things are simply not possible. Over the last few years, rapid browser implementation of advances in CSS have given us the ability to do many of these previously impossible things. We can use our new powers to build the same designs faster, or we can start to ask ourselves what we might do if we were solving these problems afresh.

In this talk, Rachel will look at the things coming into browsers right now which change the way we see web design. CSS subgrids allowing nested grids to use the track definition of their parent; logical properties and values moving the web away from the physical dimensions of a computer screen; screen experiences which behave more like an app, or even paged media, due to scroll snapping and multidimensional control. By understanding the new medium of web design we can start to imagine the future, and even help to shape it.

I’m not sure if it even makes sense to try to live-blog a code talk, but I’ll give it my best shot…

Rachel has been talking about CSS at An Event Apart for over three years now. Our understanding of the possibilities of CSS has changed a lot in that time. Our use of floats for layout is being consigned to history. It’s no less monumental than the change from tables to CSS. Tableless web design often meant simplifying our designs. We were used to designing in a graphic design tool and then slicing it up into table cells. CSS couldn’t give us the same fine-grained control so we simplified our designs. It got us to start thinking of the web as its own medium. That idea really progressed with responsive web design.

But perhaps us CSS advocates downplayed some of the issues. We weren’t trying to create new CSS, we were just trying to get people to use CSS.

What we term “good web design” is based in the technical limitations of CSS. We say “the web is not print” when we see a design that’s quite print-like. People expect to have to hack at CSS to get it to do what we want. But times have changed. We have solved many of those problems (but that doesn’t mean we got all of them!).

Rachel spends a lot of time telling designers: you never know how tall anything is on the web. It used to be a real challenge to get the top and bottom of boxes to line up. We’d have to fix the height of the boxes. And if too much content goes in, the content overflows. Then we end up limiting the amount of content at the CMS side. We hacked around the problem. A technical limitation influenced our design, and even our content management. Then we got flexbox. Not only did the problem disappear, but the default behaviour is exactly what we struggled with for years: equal height columns.

How big is this box? You’ve seen the “CSS is awesome mug”, right?

Our previous layout systems relied on percentage lengths for widths. Those values had to add up to 100%, and no more. People tried to do the same thing with flexbox. People made “grid systems” with flexbox that gave widths to everything. “Flexbox is weird!”, people said. But the real problem is that flexbox is not the layout method you think it is. It’s for taking a bunch of oddly-sized things and returning the most reasonable layout for those things. It assigns space in a smart way. That solves the problem of needing to give everthing a width. It figures it out for you. If you decide to put widths on everything, you’re kind of working against flexbox.

We’re so used to having to hack everything in CSS, we had to take a step back with flexbox and realise that hacks aren’t necessary.

CSS tries to avoid data loss. That’s why the “CSS is awesome” text overflows the box. You don’t want the text to vanish. Visible overflow is messy, but it’s better than making some content disappear.

In the box alignment specification, there’s the concept of safe and unsafe alignment. Safe:

.container {
    display: flex;
    flex-direction: column;
    align-items: safe center;
}

You give the browser permission to align items to the start if necessary. But you can override that with unsafe:

.container {
    display: flex;
    flex-direction: column;
    align-items: unsafe center;
}

Overflow is going to happen. Now it’s up to you what happens when it does.

The “content honking out of the box” problem described in the “CSS is awesome” meme is now controlled with min-content:

width: min-content;

The box expands to encompass the widest content.

You have many choices. But what if the text isn’t running left to right? It might not be a problem we run into for English text. For years, CSS had that English-centric assumption baked in. Now CSS has been updated to not make that assumption. The web is not left to right. Flexbox and grid take an agnostic approach to the writing mode of the document. There’s no “top”, “bottom”, “left” or “right”. There’s “start”, “end”, “inline” and “block”. Now we have a new spec for logical properties and values. It maps old physical values (top, bottom, etc.) to the newer agnostic values.

So even if you use writing-mode to flip direction, width is still a width. Use inline-size instead of width and everything keeps working: the width maps to height when you apply a different writing-mode value. Eventually we’ll use those flow-relative values more than the old values. Solutions need to include different writing modes.

There is no fold. We’ve said that for years, right? But we know where the fold is. We’ve got viewport units that represent the width and height of the browser viewport. We can start to make designs that make use of the viewport. You can size a screen full of images exactly to fit the visible space. Combine it with scroll-snap to get the page views to snap as the user scrolls. You get paged layout. That’s interesting for Rachel because she’s used to designing for paged layout in print versus continuous layout on the web.

What’s next for CSS grid? Grid layout has been the biggest problem-solver of recent years. But that doesn’t mean it has solved all the layout problems. New problems appear as we start to work with CSS grid. We often end up nesting grids. But the nested grids don’t have any knowledge of one another. We’re back to: you never know how tall things are on the web. We need a way to have a relationship. Some kind of, I don’t know, subgrid.

You could use display: contents. It removes a box from the visual display allowing grandchildren to act like children. The browser support is good, but there’s a stonking accessibility bug so don’t use it in production. Also you can’t apply visual styles to anything that’s got display: contents on it. But grid-template-rows: subgrid will solve this problem. The spec is in a good shape. We’re waiting for the first browser implementations.

You will hit problems. Find new technical limitations. It’s just that we can’t do that stuff yet. We get the new stuff when we create it. Write up the problems you come across.

We’re finding the edges. Rachel is going to share her problems.

Rachel wants to put some text into her image grid. No problem. But then if there’s too much text, it might not fit in a height-restricted row. We can adjust the row to not be height-restricted, but then we lose the nice viewport-fitting layout.

In continuous media—which is what the web is—content inside multicol gets longer and longer. You can fix the height of the container but then the columns get created horizontally. What if you could say, I want my multicol container to be, say 100vh high, but if the content overlows, create a new 100vh high container below. Overflow in the block dimension. Maybe that’ll be in the next version of the multicol spec.

Multicol doesn’t solve Rachel’s image grid situation. What she needs is a way for the text to fill up a box and then flow into another box. The content needs to be semantically marked up—not broken into separate chunks for layout—and we want the browser to figure out where to break that content and fill up available space.

It comes as a surprise to people that a lot of paged media—books, magazines—are laid out with CSS. It’s in the paged media module. Prince is a good example of a user agent that supports paged media. There’s the concept of a page box: a physical page into which content can go. You get to define the boxes with physical dimensions like inches or centimeters. You create a bunch of margin boxes with generated content. Enough pages are created to hold all the content. You create your page model and flow the content through it.

Maybe apps and websites with defined screens are not that different from paged contexts. There have been attempts to create CSS specs that would allow this kind of content-flowing behaviour. CSS regions was one attempt. There was -ms-flow-into and -ms-flow-from in the IE and Edge implementations. You had to apply -ms-flow-into to an iframe element.

Regions needs ready-prepared boxes for the content to flow into. But how can you know how many boxes to prepare in advance? You don’t know how big things will be on the web. Rachel has been told that there’s nothing wrong with the CSS regions spec because you can define a final bucket for all leftover content. That doesn’t seem like a viable solution.

CSS regions predated CSS grid and didn’t take off. Now that we’ve got grid, something like regions makes a lot of sense.

Web design has been involved in a constant battle with overflow. Whether it’s overflowing boxes, or there (not) being a fold, or multicol layout. Rachel thinks we can figure out a way to get regions to work. Perhaps regions paved the way for something better. Maybe it was just ahead of its time. There are a lot of things hidden away in CSS specs that never made it out: things that didn’t make sense until more advanced CSS came along.

Regions—like multicol—relies on fragmentation. Ever tried to stop a heading behind the last thing on a page in a print stylesheet? We need good support for break-inside, break-before, and break-after.

We create new things to solve problems. Maybe you don’t see the value of something like regions, but I bet there’s been something where you thought “I wish CSS could do this!”.

Rob wrote up a problem that he had with trying to have a floated element maintain its floatiness inside a grid. He saw it as a grid problem. Rachel saw it as an exclusions problem. Rob’s write-up was really valuable to demonstrate the need for exclusions. Writing things up is hugely valuable for pushing things forward. Write up your ideas—they’ll show us the use case.

Ask “why can’t I do that?” Let’s not fall into the temptation of making things grid-like just because we have CSS grid now. Keep pushing at the boundaries.

Many of things Rachel has shown—grid, exclusions, regions—were implemented by Microsoft. With Edge moving to a Chromium rendering engine, we must make sure that we maintain diversity of thought in the standards process. Voices other than those of rendering engines need to contribute to the discussion.

At a W3C meeting or standards discussion, the room should not be 60-70% Googlers.

More than ever, the web needs diversity of thought. Rachel isn’t having a dig at Google. This isn’t a fight between good and evil. It’s a fight against any monoculture. So please contribute. Get involved. Together we can work for the future of the web platform.

Generation Style by Eric Meyer

It’s time for the afternoon talks at An Event Apart in Seattle. We’re going to have back-to-back CSS, kicking off with Eric Meyer. His talk is called Generation Style. The blurb says:

Consider, if you will, CSS generated content. We can, and sometimes even do, use it to insert icons before or after pieces of text. Occasionally we even use it add a bit of extra information. And once upon a time, we pressed it into service as a hack to get containers to wrap around their floated children. That’s all fine—but what good is generated content, really? What can we do with it? What are its limitations? And how far can we push content generation in a new landscape full of flexible boxes, grids, and more? Join Eric as he turns a spotlight on generated content and shows how it can be a generator of creativity as well as a powerful, practical tool for everyday use.

Wish me luck, ‘cause I’m going to try to capture the sense of this presentation…

So we had a morning of personas and user journeys. This afternoon: code, baby! Eric is going to dive into a very specific corner of CSS—generated content. For an hour. Let’s do it!

He shows the CSS Generated Content Module Level 3. Eric wants to focus on one bit: the pseudo-elements ::before and ::after. What does pseudo-element mean?

You might have used one of these pseudo-elements for blockquotes. Perhaps you’ve put a great big quotation mark in front of them.

blockquote:: after {
    content: "“";
    font-size: 4em;
    opacity: 0.67;
/* placement styles here */
}

Why is Eric using ::after? Because you can. You can put the ::after content wherever you want. But if your placement styles fail, this isn’t a good place for the generated content. So don’t do this. Use ::before.

Another example of using generated content is putting icons beside certain links:

a[href$=".pdf"]::after {
    content: url(i/icon.png);
    height: 1em;
    margin-right: 0.5em;
    vertical-align: top;
}

But these icons look yucky. But if you use larger images, they will be shown full size. You only have so much control over what happens in there. I mean, that’s true of all CSS: think of CSS as a series of strong suggestions. But here, we have even less control than we’re used to. Why isn’t the image 1em tall like I’ve specified in the CSS? Well, the generated content box is 1em tall but the image is breaking out of this box. How about this:

a[href]::after * {
    max-width: 100%;
    max-height: 100%
}

This doesn’t work. The image isn’t an element so it can’t be selected for.

The way around it is to use background images instead:

a[href$=".pdf"]::after {
    content: '';
    height: 1em; width: 1em;
    margin-right: 0.5em;
    vertical-align: top;
    background: center/contain;
    background-image: url(i/icon.png);
}

Notice there’s a right margin there. That stretches out the width of the whole link. That’s exactly the same as if there were an actual span in there:

a[href$=".pdf"] span {
    height: 1em; width: 1em;
    margin-right: 0.5em;
    vertical-align: top;
    background: center/contain;
    background-image: url(i/icon.png);
}

So why use generated content instead of a span? So that you don’t have to put extra spans in your markup.

Generated content is great for things that work great when they’re there, but still work fine if they’re not. It’s progressive enhancement.

You’ve almost certainly used generated content for the clearfix hack.

.clearfix::after {
    content: '';
    display: table;
    clear: both;
}

Ask your parents. It’s when we wanted to make the containing element for a group of floating elements to encompass the height of those elements. Ancient history, right? Well, Eric is showing an example of a certain large media company today. There are a lot of clearfixes in there.

Eric makes the clearfix visible:

.clearfix::after {
    content: '';
    display: table;
    clear: both;
    border: 10px solid purple;
}

It looks like a span: a 10 pixel wide box. Now change the display property:

.clearfix::after {
    content: '';
    display: block;
    clear: both;
    border: 10px solid purple;
}

Now it behaves more like a div than a span.

The big question here is: who cares?

Let’s say we’re making a site about corduroy pillows (I hear they’re really making headlines).

<header>
<h1>Corduroy pillows</h1>
<p>Lorum ipsum...</p>
</header>

We can add a box under the header:

header::after {
    content: " ";
    display: block;
    height: 1em;
}

You can do stuff with that extra content, like using a linear gradient:

header::after {
    content: " ";
    display: block;
    height: 1em;
    background: linear-gradient(to right, #DDD, #000, #DDD) center / 100% 1px no-repeat;
}

The colour stops are #DDD, #000, and #DDD. You get this nice gradiated line under the header. You can chain a bunch of of radial gradients together to get some nice effects. You could mix in some background images too. Now you’ve got some on-brand separators. You could use generated content to add some “under construction” separators.

By the way, ever struggled to keep track of the order of backgrounds? Think about how you would order layers in Photoshop.

How about if we could use generated content to make design tools?

div[id]::before {
    content: attr(id);
}

Now the generated content is taken from the id attribute. You can make it look like Firebug:

div[id]::before {
    content: '#' attr(id);
    font: 0.75rem monospace;
    position: absolute;
    top: 0;
    left: 0;
    border: 1px dashed red;
    padding: 0 0.25em;
    background: #FFD;
}

You can even make the content cover the whole box with bottom and right values too:

div[id]::before {
    content: '#' attr(id);
    font: 0.75rem monospace;
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    border: 1px dashed red;
    padding: 0 0.25em;
    background: #FFD8;
}

(And yes, that is a hex value with opacity.)

Let’s make it less code-y:

div[id]::before {
    content: attr(id);
    font: bold 1.5rem Georgia serif;
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    border: 1px dashed red;
    padding: 0 0.25em;  
    background: #FFD8;
}

Throw in some text-shadow. Maybe some radial gradients. We’re at the wireframe stage. Let’s drop in some SVG images to show lines across the boxes.

How about automating design touches?

pre {
    padding: 0.75em 1.5em;
    background: #EEE;
    font: medium Consolas, monospace;
    position: relative;
}

Let’s say that applies to:

<pre class="css">
...
</pre>

You can generate labels with that class attribute:

pre::before {
    content: attr(class);
    display: block;
    padding: 0.25em 0 0.15em;
    font: bold 1em Noah, sans-serif;
    text-align: center;
    text-transform: uppercase;
}

Let’s align it to the top of it’s parent with negative margins:

pre::before {
    content: attr(class);
    display: block;
    padding: 0.25em 0 0.15em;
    margin: -0.75em -1.5em 1em;
    font: bold 1em Noah, sans-serif;
    text-align: center;
    text-transform: uppercase;
}

Or you can use absolute positioning:

pre::before {
    content: attr(class);
    display: block;
    padding: 0.25em 0 0.15em;
    position: absolute;
    top: 0;
    right: 0;
    left: 0;
    font: bold 1em Noah, sans-serif;
    text-align: center;
    text-transform: uppercase;
}

Now let’s change the writing mode:

pre::before {
    content: attr(class);
    display: block;
    padding: 0.25em 0 0.15em;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    writing-mode: vertical-rl;
    font: bold 1em Noah, sans-serif;
    text-align: center;
    text-transform: uppercase;
}

Now the text is running down the side, but it’s turned on its side. You can transform it:

pre::before {
    content: attr(class);
    display: block;
    padding: 0.25em 0 0.15em;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    font: bold 1em Noah, sans-serif;
    text-align: center;
    text-transform: uppercase;
}

But if you this, be careful. Your left margin is no longer on the left. Everything’s flipped around.

You could also update the generated content according to the value of the class attribute:

pre.css:: before {
    content: '{ CSS }';
}

pre.html::before {
    content: '< HTML >';
}

pre.js::before,
pre.javascript::before {
    content: '({ JS })();';
}

It’s presentational, so CSS feels like the right place to do this. But you can’t generate markup—just text. Angle brackets will be displayed in their raw form.

But positioning is so old-school. Let’s use CSS grid:

pre {
    display: grid;
    grid-template-columns: min-content 1fr;
    grid-gap: 0.75em;
}

pre::before {
    content: attr(class);
    margin: -1em 0;
    padding: 0.25em 0.1em 0.25em 0;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    font: bold 1em Noah, sans-serif;
    text-align: center;
    text-transform: uppercase;
}

Heck, you could get rid of the negative margins by putting the code content inside a code element and giving that a margin of 1em.

You can see generated content in action on the website of An Event Apart:

li.news::before {
    content: attr(data-cat);
    background-color: orange;
    color: white;
}

The data-cat attribute (which contains a category value) is displayed in the generated content.

Cool. That’s all stuff we can do now. What about next?

Well, suppose you had to put some legalese on your website. You could generate the numbers of nested sections:

h1 { counter-reset: section; }
h2 { counter-reset: subsection; }

Increment the numbers each time:

h2 { counter-increment: section; }
h3 { counter-increment: subsection; }

And display those values:

h2::before {
    content: counter(section) ".";
}
h2::before {
    content: counter(section) counter ":" (subsection, upper-roman);
}

Soon you’ll be able to cycle through a list of counter styles of your own creation with a @counter-style block.

But remember, if you really need that content to be visible for everyone, don’t rely on generated content: put it in your markup. It’s for styles.

So, generated content. It’s pretty cool. You can do some surprising things with it. Maybe ::before this talk, you didn’t think about generated content much, but ::after this talk ,you will.