web-design-skill/.agents/skills/web-design-engineer/references/advanced-patterns.md

Advanced Reference: Component Patterns & Code Templates

This file contains advanced patterns and code templates to reference when implementing specific tasks.

Table of Contents

1. Responsive Slide Engine
2. Device Simulation Frames
3. Tweaks Panel Implementation
4. Animation Timeline Engine
5. Design Canvas (Multi-option Comparison)
6. Dark Mode Toggle
7. Data Visualization Templates

---

Responsive Slide Engine

For building fixed-size presentations that auto-fit to any viewport.

Key conventions:

• Internal arrays use 0-indexed, but numbers displayed to the user are always 1-indexed
• Each <section class="slide"> gets data-screen-label="01 Title", data-screen-label="02 Agenda", etc. for easy reference
• Control buttons go outside the .stage scaled container to ensure usability on small screens

<style>
  * { margin: 0; padding: 0; box-sizing: border-box; }
  body { 
    background: #000; 
    display: flex; 
    align-items: center; 
    justify-content: center;
    height: 100vh;
    overflow: hidden;
    font-family: system-ui, sans-serif;
  }
  .stage {
    width: 1920px;
    height: 1080px;
    position: relative;
    transform-origin: center center;
  }
  .slide {
    position: absolute;
    inset: 0;
    display: none;
    padding: 80px;
  }
  .slide.active { display: flex; }
  .controls {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
    z-index: 1000;
  }
  .controls button {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    background: rgba(255,255,255,0.15);
    color: white;
    cursor: pointer;
    font-size: 14px;
  }
  .slide-counter {
    position: fixed;
    bottom: 20px;
    right: 20px;
    color: rgba(255,255,255,0.6);
    font-size: 14px;
  }
</style>

<script>
  // Auto-fit scaling
  function scaleStage() {
    const stage = document.querySelector('.stage');
    const scaleX = window.innerWidth / 1920;
    const scaleY = window.innerHeight / 1080;
    const scale = Math.min(scaleX, scaleY);
    stage.style.transform = `scale(${scale})`;
  }
  window.addEventListener('resize', scaleStage);
  scaleStage();

  // Slide navigation
  let current = parseInt(localStorage.getItem('slideIndex') || '0');
  const slides = document.querySelectorAll('.slide');
  
  function showSlide(n) {
    current = Math.max(0, Math.min(n, slides.length - 1));
    slides.forEach((s, i) => s.classList.toggle('active', i === current));
    localStorage.setItem('slideIndex', current);
    // Display 1-indexed to user, store 0-indexed internally
    document.querySelector('.slide-counter').textContent = `${current + 1} / ${slides.length}`;
  }
  
  document.addEventListener('keydown', e => {
    if (e.key === 'ArrowRight' || e.key === ' ') showSlide(current + 1);
    if (e.key === 'ArrowLeft') showSlide(current - 1);
  });
  
  showSlide(current);
</script>

---

Device Simulation Frames

iPhone Frame

const IPhoneFrame = ({ children, title = "App" }) => (
  <div style={{
    width: 390,
    height: 844,
    borderRadius: 48,
    border: '12px solid #1a1a1a',
    overflow: 'hidden',
    position: 'relative',
    boxShadow: '0 25px 50px -12px rgba(0,0,0,0.25)',
    background: '#fff'
  }}>
    {/* Status bar */}
    <div style={{
      height: 54,
      display: 'flex',
      alignItems: 'center',
      justifyContent: 'space-between',
      padding: '0 24px',
      fontSize: 14,
      fontWeight: 600
    }}>
      <span>9:41</span>
      <div style={{
        width: 126,
        height: 34,
        background: '#1a1a1a',
        borderRadius: 20,
        position: 'absolute',
        left: '50%',
        transform: 'translateX(-50%)',
        top: 8
      }} />
      <span>⚡ 📶</span>
    </div>
    {/* Content */}
    <div style={{ height: 'calc(100% - 54px)', overflow: 'auto' }}>
      {children}
    </div>
    {/* Home indicator */}
    <div style={{
      position: 'absolute',
      bottom: 8,
      left: '50%',
      transform: 'translateX(-50%)',
      width: 134,
      height: 5,
      background: '#1a1a1a',
      borderRadius: 3
    }} />
  </div>
);

Browser Window Frame

const BrowserFrame = ({ children, url = "https://example.com", title = "Page" }) => (
  <div style={{
    borderRadius: 12,
    overflow: 'hidden',
    boxShadow: '0 25px 50px -12px rgba(0,0,0,0.25)',
    border: '1px solid #e5e5e5'
  }}>
    {/* Title bar */}
    <div style={{
      background: '#f5f5f5',
      padding: '12px 16px',
      display: 'flex',
      alignItems: 'center',
      gap: 12,
      borderBottom: '1px solid #e5e5e5'
    }}>
      <div style={{ display: 'flex', gap: 8 }}>
        <div style={{ width: 12, height: 12, borderRadius: '50%', background: '#ff5f57' }} />
        <div style={{ width: 12, height: 12, borderRadius: '50%', background: '#febc2e' }} />
        <div style={{ width: 12, height: 12, borderRadius: '50%', background: '#28c840' }} />
      </div>
      <div style={{
        flex: 1,
        background: '#fff',
        borderRadius: 6,
        padding: '6px 12px',
        fontSize: 13,
        color: '#666',
        border: '1px solid #e0e0e0'
      }}>
        {url}
      </div>
    </div>
    {/* Content */}
    <div style={{ background: '#fff' }}>
      {children}
    </div>
  </div>
);

---

Tweaks Panel Implementation

const TweaksPanel = ({ config, onChange, visible }) => {
  if (!visible) return null;
  
  return (
    <div style={{
      position: 'fixed',
      bottom: 20,
      right: 20,
      width: 280,
      background: 'rgba(24, 24, 27, 0.95)',
      backdropFilter: 'blur(12px)',
      borderRadius: 12,
      padding: 16,
      color: '#fff',
      fontSize: 13,
      zIndex: 9999,
      boxShadow: '0 20px 60px rgba(0,0,0,0.3)',
      border: '1px solid rgba(255,255,255,0.1)'
    }}>
      <div style={{ fontWeight: 600, marginBottom: 12, fontSize: 14 }}>Tweaks</div>
      
      {Object.entries(config).map(([key, value]) => (
        <div key={key} style={{ marginBottom: 12 }}>
          <label style={{ display: 'block', marginBottom: 4, opacity: 0.7 }}>
            {key}
          </label>
          {typeof value === 'boolean' ? (
            <input
              type="checkbox"
              checked={value}
              onChange={e => onChange({ ...config, [key]: e.target.checked })}
            />
          ) : typeof value === 'number' ? (
            <input
              type="range"
              min="0"
              max="100"
              value={value}
              onChange={e => onChange({ ...config, [key]: Number(e.target.value) })}
              style={{ width: '100%' }}
            />
          ) : value.startsWith('#') ? (
            <input
              type="color"
              value={value}
              onChange={e => onChange({ ...config, [key]: e.target.value })}
            />
          ) : (
            <input
              type="text"
              value={value}
              onChange={e => onChange({ ...config, [key]: e.target.value })}
              style={{
                width: '100%',
                background: 'rgba(255,255,255,0.1)',
                border: '1px solid rgba(255,255,255,0.2)',
                borderRadius: 4,
                padding: '4px 8px',
                color: '#fff'
              }}
            />
          )}
        </div>
      ))}
    </div>
  );
};

---

Animation Timeline Engine

const useTime = (duration = 5000) => {
  const [time, setTime] = React.useState(0);
  const [playing, setPlaying] = React.useState(true);
  const frameRef = React.useRef();
  const startRef = React.useRef();
  
  React.useEffect(() => {
    if (!playing) return;
    const animate = (timestamp) => {
      if (!startRef.current) startRef.current = timestamp;
      const elapsed = (timestamp - startRef.current) % duration;
      setTime(elapsed / duration); // 0 to 1
      frameRef.current = requestAnimationFrame(animate);
    };
    frameRef.current = requestAnimationFrame(animate);
    return () => cancelAnimationFrame(frameRef.current);
  }, [playing, duration]);
  
  return { time, playing, setPlaying };
};

const Easing = {
  linear: t => t,
  easeInOut: t => t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t,
  easeOut: t => 1 - Math.pow(1 - t, 3),
  easeIn: t => t * t * t,
  spring: t => 1 - Math.pow(Math.E, -6 * t) * Math.cos(8 * t)
};

const interpolate = (t, from, to, easing = Easing.easeInOut) => {
  const progress = easing(Math.max(0, Math.min(1, t)));
  return from + (to - from) * progress;
};

// Usage example:
// const { time } = useTime(3000);
// const opacity = interpolate(time, 0, 1);
// const x = interpolate(time, -100, 0, Easing.spring);

---

Design Canvas

For displaying multiple design options side by side for comparison:

const DesignCanvas = ({ options, columns = 3 }) => (
  <div style={{
    display: 'grid',
    gridTemplateColumns: `repeat(${columns}, 1fr)`,
    gap: 24,
    padding: 40,
    background: '#f8f9fa',
    minHeight: '100vh'
  }}>
    {options.map((option, i) => (
      <div key={i} style={{
        background: '#fff',
        borderRadius: 12,
        overflow: 'hidden',
        boxShadow: '0 1px 3px rgba(0,0,0,0.1)'
      }}>
        <div style={{
          padding: '12px 16px',
          borderBottom: '1px solid #eee',
          fontSize: 13,
          fontWeight: 600,
          color: '#666'
        }}>
          Option {String.fromCharCode(65 + i)}: {option.label}
        </div>
        <div style={{ padding: 16 }}>
          {option.content}
        </div>
      </div>
    ))}
  </div>
);

---

Dark Mode Toggle

const ThemeProvider = ({ children }) => {
  const [dark, setDark] = React.useState(
    window.matchMedia('(prefers-color-scheme: dark)').matches
  );
  
  const theme = dark ? {
    bg: '#0a0a0b',
    surface: '#18181b',
    border: '#27272a',
    text: '#fafafa',
    textMuted: '#a1a1aa',
    primary: '#3b82f6'
  } : {
    bg: '#ffffff',
    surface: '#f4f4f5',
    border: '#e4e4e7',
    text: '#18181b',
    textMuted: '#71717a',
    primary: '#2563eb'
  };
  
  return (
    <ThemeContext.Provider value={{ theme, dark, setDark }}>
      <div style={{ background: theme.bg, color: theme.text, minHeight: '100vh' }}>
        {children}
      </div>
    </ThemeContext.Provider>
  );
};

---

Data Visualization Templates

Chart.js Quick Start

<canvas id="myChart" width="800" height="400"></canvas>
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
<script>
  const ctx = document.getElementById('myChart').getContext('2d');
  new Chart(ctx, {
    type: 'line', // bar, pie, doughnut, radar, etc.
    data: {
      labels: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun'],
      datasets: [{
        label: 'Revenue',
        data: [12, 19, 3, 5, 2, 3],
        borderColor: '#3b82f6',
        backgroundColor: 'rgba(59, 130, 246, 0.1)',
        tension: 0.4,
        fill: true
      }]
    },
    options: {
      responsive: true,
      plugins: {
        legend: { display: false }
      },
      scales: {
        y: { beginAtZero: true, grid: { color: '#f0f0f0' } },
        x: { grid: { display: false } }
      }
    }
  });
</script>

---

Color System Best Practices

Use oklch to define a harmonious color system:

:root {
  /* oklch-based color system */
  --primary-h: 250;  /* hue */
  --primary: oklch(0.55 0.25 var(--primary-h));
  --primary-light: oklch(0.75 0.15 var(--primary-h));
  --primary-dark: oklch(0.35 0.2 var(--primary-h));
  
  /* Neutrals */
  --gray-50: oklch(0.98 0.002 250);
  --gray-100: oklch(0.96 0.004 250);
  --gray-200: oklch(0.92 0.006 250);
  --gray-300: oklch(0.87 0.008 250);
  --gray-400: oklch(0.71 0.01 250);
  --gray-500: oklch(0.55 0.014 250);
  --gray-600: oklch(0.45 0.014 250);
  --gray-700: oklch(0.37 0.014 250);
  --gray-800: oklch(0.27 0.014 250);
  --gray-900: oklch(0.21 0.014 250);
}

---

Font Recommendations (Non-default Choices)

⚠️ These are experience-based suggestions, not hard rules.

• Always prefer fonts already specified by the brand or design system; only refer to this table when the user hasn't provided any font scheme.
• The only hard rule: Avoid Inter / Roboto / Arial / Fraunces / system-ui — fonts overused by AI-generated content that instantly signal "this was assembled by AI."
• When choosing fonts, focus on "personality fit" rather than "what's trendy." The table below lists common high-quality choices, not an exhaustive list.

Use Case	Recommendation	Google Fonts Name
Modern headings	Plus Jakarta Sans	Plus+Jakarta+Sans
Elegant body text	Outfit	Outfit
Technical feel	Space Grotesk	Space+Grotesk
Premium brand	Sora	Sora
Editorial feel	Newsreader	Newsreader
Handwritten style	Caveat	Caveat
Monospace / code	JetBrains Mono	JetBrains+Mono

<link href="https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap" rel="stylesheet">

---

Color × Font Pairing Reference

⚠️ These are experience-based pairing suggestions, not hard rules. When you have absolutely no design context, pick one as a starting point — it's far better than starting from Inter + #3b82f6. Once the user provides a brand / design system / reference site, drop this table immediately and follow their materials.

For quickly establishing a visual system with personality:

Style	Primary Color (oklch)	Font Pairing	Best For
Modern tech	oklch(0.55 0.25 250) blue-violet	Space Grotesk + Inter	SaaS, dev tools, AI products
Elegant editorial	oklch(0.35 0.10 30) warm brown	Newsreader + Outfit	Content platforms, blogs, editorial
Premium brand	oklch(0.20 0.02 250) near-black	Sora + Plus Jakarta Sans	Luxury, consulting, finance
Lively consumer	oklch(0.70 0.20 30) coral	Plus Jakarta Sans + Outfit	E-commerce, lifestyle, social
Minimal professional	oklch(0.50 0.15 200) teal-blue	Outfit + Space Grotesk	Data products, dashboards, B2B
Artisan warmth	oklch(0.55 0.15 80) caramel	Caveat (decorative) + Newsreader	Food & beverage, education, creative

Avoid these combos:

• ❌ Inter + Roboto + blue buttons (peak AI aesthetic)
• ❌ Fraunces + purple-pink gradients (overused)
• ❌ More than three font families (visual chaos)