CSS Unit Guide
- px: Absolute pixel. Ignores user browser font settings.
- rem: Relative to the root (<html>) font size. Best for accessible, scalable layouts.
- em: Relative to the parent element's font size. Can cascade unexpectedly.
- pt: Points — 1pt = 1/72 inch. Used in print CSS.
- vw/vh: 1vw = 1% of viewport width. Great for responsive typography.