CSS layout from the inside out

CSS Layout from the inside out Rachel Andrew, State of the Browser, October, 2021

The Holy Grail

target / context = result Fluid Grids, Ethan Marcotte, A List Apart, 2009.

A float-based grid Size things with % and push them around to look like a grid.

.box { float: left; } .a { width: 25%; } .b { width: 16.66%; } .c {width: 33.33%; }

The biggest problems in (float-based) web design? Clearing floats and getting equal height columns.

A flex-based grid Size things with % and push them around to look like a grid (but with equal height columns)

.wrapper { display: flex; } .box { flex: none; } .a { width: 25%; } .b { width: 16.66%; } .c {width: 33.33%; }

The biggest problem in (flex-based) web design? Flexbox being weird and hard.

.wrapper { display: grid; grid-template-columns: repeat(12,minmax(0,1fr); } .a { grid-column: auto / span 3; } .b { grid-column: auto / span 2; } .c {grid-column: auto / span 4; }

Has grid made flexbox redundant?

.grid { display: grid; grid-template-columns: repeat(6,minmax(0,1fr)); }

minmax(0,1fr)

minmax(auto,1fr)

h1 { display: grid; grid-template-columns: 1fr auto 1fr; } h1::before, h1::after { content: “”; border-top: 1px solid var(—charcoal); align-self: center; }

Aspect Ratios

The “padding hack” https://css-tricks.com/aspect-ratio-boxes/

aspect-ratio: 16/9;

.wrapper { display: grid; grid-template-columns: 200px 350px; } .box16x9 { aspect-ratio: 16/9; } .box4x3 { aspect-ratio: 4/3; }

1fr 1fr 1fr

CSS Containment This box and children are independent from the rest of the layout.

.sidebar { contain: layout; }

Container Queries Design components that can react to the available space in their container.

Try out Container Queries In chrome://flags enable “CSS Container Queries”.

.sidebar { container-type: inline-size; }

Using container-type creates a containment context. This also turns on layout, style, and inline-size containment, in the same way as using the contain property does.

.sidebar { container-type: inline-size; container-name: sidebar; }

@container (min-width: 400px) { .card { display: grid; grid-template-columns: 1fr 2fr; } }

@container sidebar (min-width: 400px) { .card { display: grid; grid-template-columns: 1fr 2fr; } }

.wrapper > div { container-type: inline-size; } @container (min-width: 220px) { .box { background-color: var(—blue-sapphire); } }

.fig-panel { display: grid; grid-template-columns: 1fr 1fr; }

@container (min-width: 700px) { grid-template-columns: repeat(3,1fr); }

This seems so simple! Why did it take so long?

.sidebar { container: inline-size / sidebar; }

.feature { container-type: block-size; container-name: feature; }

Container Queries are coming But they probably aren’t the solution to all your problems.

Remember than flexbox is designed for flexible things A bunch of different sized items, within an unknown container size, dealt with as a group.

Use intrinsic and range sizing methods with grid minmax(), min-content, max-content, auto, and fit-content()

But, do get excited for Container Queries! Try it out! If you spot any issues or think of a potential enhancement, let the CSS Working Group know:

Thank you! Find me @rachelandrew Slides at: https://noti.st/rachelandrew