Tags: styling



Thursday, March 26th, 2020

CSS Can Influence Screenreaders | Ben Myers

This surprises me. But forewarned is forearmed.

Tuesday, March 24th, 2020

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:


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:


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:

allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture"

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:


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:

<a class="videoimglink" href="'.$url.'">
<img width="100%" loading="lazy"
https://i.ytimg.com/vi/'.$id.'/mqdefault.jpg 320w,
https://i.ytimg.com/vi/'.$id.'/hqdefault.jpg 480w,
https://i.ytimg.com/vi/'.$id.'/maxresdefault.jpg 1280w

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).

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:


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


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:

<a class="videoimglink" href="https://www.youtube.com/watch?v=-eiqhVmSPcs"
this.parentNode.innerHTML='<iframe src=https://www.youtube-nocookie.com/embed/-eiqhVmSPcs?autoplay=1></iframe>'">
<img width="100%" loading="lazy"
alt="The Banks Of Lough Gowna (jig) on mandolin"
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

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: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).

Sunday, March 15th, 2020

Twitter thread as blog post: Thoughts on how we write CSS | Lara Schenck

CSS only truly exists in a browser. As soon as we start writing CSS outside of the browser, we rely on guesses and memorization and an intimate understanding of the rules. A text editor will never be able to provide as much information as a browser can.

Thursday, March 12th, 2020

Pure CSS Landscape - An Evening in Southwold

This is not an image format. This is made of empty elements styled with CSS. (See for yourself by changing the colour value of the sun.)

Wednesday, March 11th, 2020

Why is CSS frustrating? ・ Robin Rendle

CSS is frustrating because you have to actually think of a website like a website and not an app. That mental model is what everyone finds so viscerally upsetting. And so engineers do what feels best to them; they try to make websites work like apps, like desktop software designed in the early naughts. Something that can be controlled.

Friday, February 28th, 2020

Why is CSS Frustrating? | CSS-Tricks

Why do people respect JavaScript or other languages enough to learn them inside-out, and yet constantly dunk on CSS?

The headline begs the question, but Robin makes this very insightful observation in the article itself:

I reckon the biggest issue that engineers face — and the reason why they find it all so dang frustrating — is that CSS forces you to face the webishness of the web. Things require fallbacks. You need to take different devices into consideration, and all the different ways of seeing a website: mobile, desktop, no mouse, no keyboard, etc. Sure, you have to deal with that when writing JavaScript, too, but it’s easier to ignore. You can’t ignore your the layout of your site being completely broken on a phone.

Thursday, February 20th, 2020

monica.css – Monica Dinculescu

Monica shares the little snippet of handy CSS she uses at the start of any project.

Saturday, February 15th, 2020

Same HTML, Different CSS

Like a little mini CSS Zen Garden, here’s one compenent styled five very different ways.

Crucially, the order of the markup doesn’t consider the appearance—it’s concerned purely with what makes sense semantically. And now with CSS grid, elements can be rearranged regardless of source order.

CSS is powerful and capable of doing amazingly beautiful things. Let’s embrace that and keep the HTML semantical instead of adapting it to the need of the next design change.

Friday, February 14th, 2020

A Complete Guide to Links and Buttons | CSS-Tricks

Chris takes two side-by-side deep dives; one into the a element, the other into the button element.

Even if you think you already know those elements well, I bet there’ll be something new here for you. Like, did you know that the button element can have form over-riding attributes like formaction, formenctype, formmethod, formnovalidate, and formtarget?

Monday, February 10th, 2020

Custom Styling Form Inputs With Modern CSS Features | CSS-Tricks

It’s now easier than ever to style form controls without sacrificing semantics and accessibility:

The reason is that we can finally style the ::before and ::after pseudo-elements on the <input> tag itself. This means we can keep and style an <input> and won’t need any extra elements. Before, we had to rely on the likes of an extra <div> or <span>, to pull off a custom design.

The demo is really nice. And best of all, you can wrap all of these CSS enhancements in a feaure query:

Hopefully, you’re seeing how nice it is to create custom form styles these days. It requires less markup, thanks to pseudo-elements that are directly on form inputs. It requires less fancy style switching, thanks to custom properties. And it has pretty darn good browser support, thanks to @supports.

Friday, October 25th, 2019

The difference between HTML, CSS, and JavaScript | Zell Liew

HTML lets you create the structure of a website.

CSS lets you make the website look nice.

JavaScript lets you change HTML and CSS. Because it lets you change HTML and CSS, it can do tons of things.

Sunday, October 6th, 2019

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:

<source media="(prefers-color-scheme: dark)" srcset="https://api.mapbox.com/styles/v1/mapbox/dark-v10/static...">
<img src="https://api.mapbox.com/styles/v1/mapbox/outdoors-v10/static..." alt="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.

Friday, October 4th, 2019

Designing a focus style | Zell Liew

A deep dive info focus styles with this conclusion:

The default focus ring works. There are problems with it, but it can be good enough, especially if you can’t dedicate time and energy to create a custom focus ring.

Thursday, October 3rd, 2019

A Modern CSS Reset - Andy Bell

Some very smart ideas in here for resetting default browser styles, like only resetting lists that have classes applied to them:

ol[class] {
  padding: 0;

I select only lists that do have a class attribute because if a plain ol’ <ul> or <ol> gets used, I want it to look like a list. A lot of resets, including my previous ones, aggressively remove that.

Wednesday, September 18th, 2019

Keeping it simple with CSS that scales - Andy Bell

The transcript of Andy’s talk from this year’s State Of The Browser conference.

I don’t think using scale as an excuse for over-engineering stuff—especially CSS—is acceptable, even for huge teams that work on huge products.

Tuesday, July 16th, 2019

Initial thoughts on standardizing form controls | Greg Whitworth

Greg has done a lot of research into developer frustrations with customising form controls.

My current thinking in this space, and I know some folks will find this controversial, but I think we should completely standardize in-page form controls with no limitations on their styling capabilities. What do I mean by in-page controls? I am referring to any form control or component that is rendered within the content process. This standardization would include the sub-parts and their related states and how these are exposed (probably through CSS psuedo classes or HTML attributes). This will enable the shadow-dom to be encapsulated while providing web developers with a consistent experience to adjust to match their brand and needs of their site/application.

Sunday, June 16th, 2019

This page is a truly naked, brutalist html quine.

What you see really is what you get. I like this style!

Thursday, April 18th, 2019

Fading out siblings on hover in CSS | Trys Mudford

Well, the clever CSS techniques just keep on comin’ from Trys—I’m learning so much from him!

Sunday, April 7th, 2019

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.


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!

Friday, March 15th, 2019

BEM: 4 Hang-Ups & How It Will Help Your CSS Organization

A few common gotchas when using BEM, and how to deal with them.