Writes Baseline 2026 native CSS: Flexbox/Grid/subgrid, logical properties, container queries, @layer/@scope, :has, oklch, nesting, anchor positioning, and fluid type. Use when writing or reviewing stylesheets, layout, dark mode, or cascade without a preprocessor. Not for Tailwind v4 @theme setup (setup-tailwind-typescript), glassmorphism recipes, or Sass/CSS-in-JS. Never default to physical margin-left/width when logical properties apply.
