Why Relative Units Still Matter for CSS Typography
The old advice was simple: never use px for font sizes because it locked text scaling. That’s no longer the whole story—browser zoom now handles page-wide enlargement smoothly, even with pixel-based type.
Still, as Kathleen McMahon’s deep dive argues, switching all type-related properties—both font-size and line-height—to relative units remains worthwhile. Pixel values block the font-size adjustments some users rely on in browser settings, and relative units preserve layout fidelity during zoom, which nearly everyone uses.
