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Web Development

Build, debug, and deploy websites with HTML, CSS, JavaScript, modern frameworks, and production best practices.

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SKILL.md
Quality
Evals
Security

Quick Reference

NeedSee
HTML/CSS issueshtml-css.md
JavaScript patternsjavascript.md
React/Next.js/frameworksframeworks.md
Deploy to productiondeploy.md
Performance/SEO/a11yperformance.md

Critical Rules

  1. DOCTYPE matters — Missing <!DOCTYPE html> triggers quirks mode; layouts break unpredictably
  2. CSS specificity beats cascade — .class overrides element selectors regardless of order
  3. === not == — Type coercion causes "0" == false to be true
  4. Async/await in loops — forEach doesn't await; use for...of or Promise.all
  5. CORS is server-side — No client-side fix; configure Access-Control-Allow-Origin on the server
  6. Responsive = viewport meta — Without <meta name="viewport">, mobile renders desktop-width
  7. Form without preventDefault — Page reloads; call e.preventDefault() in submit handler
  8. Images need dimensions — Missing width/height causes layout shift (CLS penalty)
  9. HTTPS or blocked — Mixed content (HTTP resources on HTTPS pages) gets blocked by browsers
  10. Environment variables leak — NEXT_PUBLIC_* exposes to client; never prefix secrets

Common Requests

"Make it responsive" → Mobile-first CSS with media queries; test at 320px, 768px, 1024px "Deploy to production" → See deploy.md for Vercel/Netlify/VPS patterns "Fix CORS error" → Server must send headers; proxy through same-origin if you can't control server "Improve performance" → Lighthouse audit; focus on LCP, CLS, FID; lazy-load below-fold images "Add SEO" → Title/description per page, semantic HTML, OG tags, sitemap.xml

Framework Decision Tree

  • Static content, fast builds → Astro or plain HTML
  • Blog/docs with MDX → Astro or Next.js App Router
  • Interactive app with auth → Next.js or Remix
  • Full SSR/ISR control → Next.js
  • Simple SPA, no SEO needed → Vite + React/Vue
Repository
onesixeight/IronMarket
Commit

d8f6cf2

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