:root {
  /* Light Theme (default) */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent-1: #1a365d;
  --accent-2: #2b6cb0;
  --accent-3: #3b82f6;
  --accent-gradient: linear-gradient(135deg, #1a365d 0%, #2b6cb0 50%, #3b82f6 100%);
  --accent-glow: rgba(59, 130, 246, 0.3);

  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.5);
  --glass-blur: 12px;
  --glass-shadow: 0 8px 32px rgba(31, 38, 135, 0.08);

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);

  /* Particles */
  --particle-color: rgba(26, 54, 93, 0.6);
  --particle-line: rgba(43, 108, 176, 0.15);

  /* Spacing */
  --section-padding: 100px;
  --container-width: 1100px;
  --card-radius: 16px;
  --border-radius-sm: 8px;
  --border-radius-lg: 24px;

  /* Typography */
  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  --transition-theme: 0.4s cubic-bezier(0.4, 0, 0.2, 1);

  /* Timeline */
  --timeline-line: #e2e8f0;
  --timeline-dot: #2b6cb0;
  --timeline-dot-active: #3b82f6;

  /* Progress bars */
  --bar-bg: #e2e8f0;
  --bar-fill: var(--accent-gradient);
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --accent-1: #38bdf8;
  --accent-2: #7dd3fc;
  --accent-3: #0ea5e9;
  --accent-gradient: linear-gradient(135deg, #0ea5e9 0%, #38bdf8 50%, #7dd3fc 100%);
  --accent-glow: rgba(56, 189, 248, 0.3);

  /* Glassmorphism - Dark */
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(56, 189, 248, 0.15);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);

  /* Shadows - Dark */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.5);

  /* Particles - Dark */
  --particle-color: rgba(56, 189, 248, 0.6);
  --particle-line: rgba(125, 211, 252, 0.12);

  /* Timeline - Dark */
  --timeline-line: #334155;
  --timeline-dot: #38bdf8;
  --timeline-dot-active: #7dd3fc;

  /* Progress bars - Dark */
  --bar-bg: #334155;
}