HTML & CSS Frontend Standards

For projects built with plain HTML, CSS, and vanilla/light JavaScript — marketing sites, documentation sites, small static tools, or the foundation any framework ultimately compiles down to. Extends the framework-agnostic rules in the core-standards skill with concrete HTML/CSS syntax, patterns, and tooling.

When to use this skill

• Setting up or reviewing a static site, landing page, or documentation site with no JS framework.
• Writing or auditing raw .html/.css files for semantics, accessibility, or performance.
• Generating a CLAUDE.md/.cursor/rules/AGENTS.md for a non-framework project.
• Reviewing a PR that touches markup or stylesheets for div-soup, missing alt text, layout-shift risk, or inconsistent spacing/typography.

Quick reference