css-structure
vmain
Where CSS should live. Claude defaults to dumping a giant <style> block or scattering style="..." attributes instead of putting styles in a .css file and linking it. Use when building or editing a web page or component, or whenever about to write a style attribute or an embedded style block. Covers defaulting to an external stylesheet, why inline style attributes are a trap, and the few cases where inline is actually correct (dynamic values via custom properties, critical CSS, single-file artifacts, email).