site/docs/css.md

CSS

Font sizes and units

It's rem all the way. The base font size is defined as px-based variable and set once the html root element. All other font sizes and spacing values are set as rem units, being nicely relative to the root font size.

html { font-size: 18px; }
p    { font-size: 1rem; }

Vendor Prefixes

Just write the official, unprefixed syntax for all CSS 3 features, no need to write the vendor prefixed versions.

Autoprefixer handles that for you automatically based on the browser versions defined in the task and data from Can I Use.

SVG sprite

All icons and most assets are SVGs. A gulp task grabs all svg files from the img/ folder and puts them as <symbol> into one SVG sprite file. Reference those icons with the SVG <use> element and their ID in the HTML where you want them to be:

<svg class="logo" aria-labelledby="title">
    <title>Logo</title>
    <use xlink:href="/assets/img/sprite.svg#logo"></use>
</svg>