Fast and Reliable CSS

Fast and Reliable CSS: Will It Work Everywhere? Browser Support and @supports, CSS Performance: What Slows a Page, and Critical CSS.

Updated

  1. Will It Work Everywhere? Browser Support and @supports (Journeyman): Check whether a CSS feature works in your readers' browsers with Baseline and caniuse.com, then use it safely with fallbacks the cascade gives you for free, @supports, and progressive enhancement.
  2. CSS Performance: What Slows a Page, and Critical CSS (Freelancer): See why a stylesheet holds up the first paint, find unused CSS with the Coverage panel, animate transform instead of layout, skip off-screen work with content-visibility, inline the critical CSS, and measure the result with Lighthouse.