Heydon/fukol-grids
The most minimal responsive, flexible grid library you can find. In fact, here’s the whole thing:
.fukol-grid {
display: flex; /* 1 */
flex-wrap: wrap; /* 2 */
margin: -0.5em; /* 5 (edit me!) */
}
.fukol-grid > * {
flex: 1 0 5em; /* 3 (edit me!) */
margin: 0.5em; /* 4 (edit me!) */
}