CSS Mistakes That Kill Performance (And How to Fix Them)

CSS can be surprisingly expensive when written poorly.

Common Problems

• Deep or complex selectors
• Overuse of box-shadow and filter
• Animating top, left, width, height
• Huge global stylesheets

Fixes

• Prefer class selectors
• Animate only transform and opacity
• Reduce repaint-heavy effects
• Split CSS by page or component
• Remove unused styles regularly

⚡ Lightweight CSS = faster rendering.