Use CSS containment to limit repaint scope

By default, a CSS change anywhere on the page can potentially affect any other element's layout. CSS containment declares that certain elements are isolated — changes inside them don't affect the outside world. This lets browsers skip large portions of the rendering pipeline for unchanged content, which is especially valuable for pages with many independent components.

Quick Reference

• contain: layout style paint tells the browser a component is visually self-contained
• content-visibility: auto skips rendering off-screen content entirely
• Containment limits how far layout recalculations need to propagate
• Use contain: strict for widgets with no overflow that shouldn't affect the page

Check

Identify components in this CSS that are visually self-contained (no overflow, no interaction with elements outside) and could benefit from CSS containment.

Fix

Add appropriate contain values to self-contained components. Add content-visibility: auto to repeated off-screen list items.