What’s !important #16: sibling-index() Animations, Use Cases for the infinity Keyword, Container Stuck Queries, and More

The soon-Baseline sibling-index() function for animations, CSS and the 2026 FIFA World Cup, use cases for the infinity keyword, container "stuck" queries, and more. What’s !important #16: sibling-index() Animations, Use Cases for the infinity Keyword, Container Stuck Queries, and More originally handwritten and published with love on CSS-Tricks . You should really get the newsletter as well.