border-box is da shiz.
Root element as border-box and everything else inherit.
Feb 1st International Box Sizing awareness day.
Specificity sucks.
Positioning, also sucks. position: sticky has an upcoming spec.
Psuedo elements, attr() "function" for content attribute of psuedo element. "currentColor" on psudeo elements totally works apparently.
CSS Alignment is a pain. CSS Tricks Centering Guide
Flexbox Froggy and Flexbox Defense. What the flexbox.
Variables: use Sass or Less. But watch for too much nesting! Mixins are nice (although sometimes, I've noticed unncessary).
Autoprefixer FTW!
PostCSS is fast build time and is awesome.
CSSNext!
Do I use (tool for analyzing CSS for unsupported things)
Problem: ALL CSS IS GLOBAL.
css-loader in Webpack.
Lint your CSS. (Stylelint)
It (CSS) can get out of hand quicker than your JavaScript can.