Answer
CSS performance work reduces unnecessary transfer, style calculation, layout, paint, and compositing. • Remove unused rules and avoid shipping large style sheets to pages that do not need them. • Prefer simple maintainable selectors and avoid repeated layout-triggering script changes. • Measure with browser performance tools before and after optimization.
💡 Simple Example
.offscreen-panel {
content-visibility: auto;
contain-intrinsic-size: auto 40rem;
}
⚡ Quick Revision
Optimize measured bottlenecks across loading, style calculation, layout, and paint.