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name: Website description: Build fast, accessible, and SEO-friendly websites with modern best practices. metadata: {"clawdbot":{"emoji":"🌐","os":["linux","darwin","win32"]}}

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Website Development Rules

Performance

Images are the #1 cause of slow sites — use WebP/AVIF, lazy-load below-the-fold, and set explicit width/height to prevent layout shift

Render-blocking CSS delays first paint — inline critical CSS in , defer the rest

Third-party scripts (analytics, chat widgets) often add 500ms+ — load them with async or defer, audit regularly

Fonts cause invisible text flash (FOIT) — use font-display: swap and preload critical fonts

Measure with Lighthouse in incognito mode — extensions skew results

Mobile First

Start CSS with mobile styles, add complexity with min-width media queries — easier to scale up than strip down

Touch targets need 44x44px minimum — fingers are imprecise, small buttons frustrate users

Test on real devices, not just browser DevTools — throttling simulation misses real-world jank

Horizontal scroll is a critical bug — test every page at 320px width minimum

viewport meta tag is required:

Accessibility

Every needs alt text — empty alt="" for decorative images, descriptive text for meaningful ones

Color contrast ratio 4.5:1 minimum for body text — use WebAIM contrast checker

Form inputs must have associated elements — placeholders alone are not accessible

Keyboard navigation must work — test every interactive element with Tab key

Screen readers announce heading hierarchy — use H1-H6 in logical order, never skip levels

HTML Structure

One

per page only — it's the page title, not a styling tool

Use semantic elements:

for actions, for navigation — don't use divs with click handlers

External links should have rel="noopener" — prevents security vulnerability with target="_blank"

Validate HTML — broken markup causes unpredictable rendering across browsers

CSS Patterns

Avoid !important — it breaks cascade and makes debugging painful. Fix specificity instead

Use relative units (rem, em, %) over fixed px for text — respects user font size preferences

CSS custom properties (variables) reduce repetition — define colors and spacing once, use everywhere

Flexbox for 1D layouts, Grid for 2D — don't force one to do the other's job

Test without CSS loading — content should still be readable in plain HTML

Common Mistakes

Missing favicon causes 404 spam in server logs — always include one, even a simple PNG

Not setting breaks screen reader pronunciation

Hardcoded http:// links break on HTTPS sites — use protocol-relative // or always https://

Assuming JavaScript is available — core content should work without JS (progressive enhancement)

Forgetting print styles — add @media print for pages users might print (receipts, articles)

Before Launch

Test all forms actually submit — broken contact forms lose leads silently

Check 404 page exists and is helpful — default server 404 looks unprofessional

Verify social sharing previews with Open Graph tags — test in Facebook/Twitter debuggers

Submit sitemap to Google Search Console — speeds up indexing

Set up uptime monitoring — know when your site goes down before users tell you