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name: web-design description: Web/CSS implementation patterns for building polished frontends. Use when implementing designs in HTML/CSS, building components, or creating responsive web interfaces.

web-design

CSS implementation patterns for building distinctive web interfaces.

Scope

This skill covers web implementation—the CSS, HTML, and patterns needed to build polished frontends. For design theory (typography choices, color systems, hierarchy principles), see design-principles.

Routing

Based on what you're building, I'll reference the appropriate implementation guide:

CSS System Setup

When: Starting a project, establishing CSS architecture Reference: references/css-system.md

• CSS custom properties (variables)
• Token systems (spacing, sizing, colors)
• Theme structure and dark mode
• Reset and baseline styles

Component Patterns

When: Building UI components, semantic markup Reference: references/components.md

• Semantic HTML structure
• BEM-style naming conventions
• Common component patterns (cards, buttons, forms)
• Accessibility patterns

Backgrounds & Depth

When: Adding visual interest, creating depth Reference: references/backgrounds.md

• Gradient techniques
• Pattern overlays
• Texture and noise
• Layered compositions

Responsive Design

When: Mobile-first, breakpoints, fluid layouts Reference: references/responsive.md

• Breakpoint systems
• Fluid typography and spacing
• Container queries
• Layout patterns (grid, flexbox)

Quick Reference

Essential CSS Variables

Copy:root {
  /* Colors - from design-principles */
  --color-primary: #0066FF;
  --color-accent: #FF6B35;
  --color-bg: #FAFAFA;
  --color-surface: #FFFFFF;
  --color-text: #1A1A1A;
  --color-text-secondary: #666666;

  /* Spacing scale */
  --space-1: 0.25rem;  /* 4px */
  --space-2: 0.5rem;   /* 8px */
  --space-3: 0.75rem;  /* 12px */
  --space-4: 1rem;     /* 16px */
  --space-6: 1.5rem;   /* 24px */
  --space-8: 2rem;     /* 32px */
  --space-12: 3rem;    /* 48px */

  /* Typography */
  --font-sans: 'IBM Plex Sans', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);

  /* Transitions */
  --transition-fast: 150ms ease-out;
  --transition-base: 200ms ease-out;
  --transition-slow: 300ms ease-out;
}

Dark Mode Pattern

Copy@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0A0A0A;
    --color-surface: #1A1A1A;
    --color-text: #FAFAFA;
    --color-text-secondary: #A0A0A0;
  }
}

Responsive Breakpoints

Copy/* Mobile first */
.component { /* mobile styles */ }

@media (min-width: 640px) { /* sm */ }
@media (min-width: 768px) { /* md */ }
@media (min-width: 1024px) { /* lg */ }
@media (min-width: 1280px) { /* xl */ }

Anti-Patterns

• Inline styles instead of CSS variables
• Magic numbers instead of spacing scale
• Pixel units for typography (use rem)
• No dark mode consideration
• Div soup instead of semantic HTML
• Ignoring focus states

Related Skills

• design-principles - Theory behind the choices
• swift-ui - iOS/SwiftUI implementation
• design-review - Audit and polish