/* ==========================================================================
   GBblitz - Googlebook / Gemini Cinematic Dark Mode Theme
   ========================================================================== */

:root {
  /* Core Dark Mode Canvas */
  --bg-black: #000000;
  --bg-glow-blue: #142743;
  
  /* Googlebook UI Windows */
  --bg-surface: #161a1e;          /* Main Window Color */
  --bg-surface-inner: #292c34;    /* Inner Window Color */
  --bg-surface-secondary: #323d4e;/* Header and Secondary Color */
  --bg-surface-elevated: #1e2329;
  
  /* Primary Accent Colors (used sparsely as tertiary accents) */
  --accent-blue: #3186ff;
  --accent-green: #0ebc5f;
  --accent-yellow: #ffcc00;
  --accent-red: #ff4641;
  
  /* Sparse Gradient Accents (Official Google Workspace Palette) */
  --googlebook-gradient: linear-gradient(90deg, #3186ff 0%, #0ebc5f 33%, #ffcc00 66%, #ff4641 100%);
  --googlebook-border-glow: linear-gradient(135deg, #3186ff 0%, #0ebc5f 38%, #ffcc00 70%, #ff4641 100%);
  --googlebook-soft-glow: linear-gradient(135deg, rgba(49, 134, 255, 0.7) 0%, rgba(14, 188, 95, 0.5) 38%, rgba(255, 204, 0, 0.5) 70%, rgba(255, 70, 65, 0.7) 100%);
  --grad-blue: linear-gradient(90deg, #1a73e8 0%, #A9A8FF 100%);
  --grad-sentiment: linear-gradient(90deg, #3387ff 0%, #a9a8ff 100%);
  --grad-teachback: linear-gradient(90deg, #0ebc5f 0%, #78c9ff 100%);
  --grad-wave-1: linear-gradient(90deg, #3387ff 0%, #a9a8ff 100%);
  --grad-red: linear-gradient(90deg, #ea4335 0%, #FF63A0 100%);
  --grad-yellow: linear-gradient(90deg, #f9ab00 0%, #FFB5E8 100%);
  --grad-green: linear-gradient(90deg, #34a853 0%, #78C9FF 100%);
  --grad-purple: linear-gradient(90deg, #a142f4 0%, #64AFFF 100%);
  --grad-workspace: linear-gradient(135deg, #64AFFF 0%, #34a853 50%, #FFF549 100%);

  /* Borders & Dividers */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-medium: rgba(255, 255, 255, 0.14);
  --border-active: rgba(49, 134, 255, 0.5);

  /* Typography Colors */
  --text-primary: #ffffff;
  --text-secondary: #9aa0a6;
  --text-muted: #5f6368;
  
  /* Googlebook Geometry */
  --radius-card: 25px;            /* 25px Rounded Corners specified in design */
  --radius-inner: 16px;
  --radius-pill: 9999px;
  --radius-sm: 8px;
  
  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.5s cubic-bezier(0.16, 1, 0.3, 1);

  /* Typography */
  --font-main: 'Google Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'Space Grotesk', monospace;

  /* Layout Geometry */
  --docked-header-height: 94px;
}