Why CSS Performance Matters

Clean, efficient CSS reduces render times and avoids layout shifts that frustrate users.

Use CSS Custom Properties

Variables improve consistency:

:root {
  --brand-color: #0070f3;
}
.button {
  color: var(--brand-color);
}

Replace Floats With Flexbox and Grid

Modern layout systems reduce hacky HTML and improve responsiveness.

Use clamp() for Fluid Typography

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
}

Logical Properties for Better Internationalisation

Use margin-inline instead of margin-left for RTL compatibility.

Audit Unused CSS

• Use DevTools coverage report
• Remove legacy framework styles
• Split CSS by route where possible

A cleaner stylesheet leads to faster pages and easier design iteration.