:root {
  /* === BRAND COLORS === */
  --color-primary: #6366f1;
  --color-primary-dark: #4f46e5;
  --color-primary-light: #818cf8;
  --color-secondary: #06b6d4;
  --color-secondary-dark: #0891b2;

  /* === CALCULATOR ACCENT COLORS === */
  --calc-home-loan: #6366f1;
  --calc-car-loan: #06b6d4;
  --calc-sip: #10b981;
  --calc-fd: #f59e0b;
  --calc-gst: #ef4444;
  --calc-salary: #8b5cf6;
  --calc-comparison: #ec4899;
  --calc-inflation: #14b8a6;
  --calc-tax: #f97316;

  /* === SEMANTIC COLORS === */
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;

  /* === LIGHT THEME SURFACES === */
  --bg-body: #f1f5f9;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --bg-sidebar: #ffffff;
  --bg-topbar: rgba(255,255,255,0.9);
  --bg-input: #f8fafc;
  --bg-input-focus: #ffffff;
  --bg-overlay: rgba(15,23,42,0.5);

  /* === LIGHT THEME TEXT === */
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  /* === LIGHT THEME BORDERS === */
  --border-color: #e2e8f0;
  --border-color-strong: #cbd5e1;
  --border-focus: var(--color-primary);

  /* === SHADOWS (LIGHT) === */
  --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.05), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.05);
  --shadow-xl: 0 20px 50px rgba(0,0,0,0.1), 0 8px 20px rgba(0,0,0,0.06);
  --shadow-glow: 0 0 30px rgba(99,102,241,0.25);
  --shadow-card: 0 4px 24px rgba(0,0,0,0.06);

  /* === GLASSMORPHISM === */
  --glass-bg: rgba(255,255,255,0.75);
  --glass-border: rgba(255,255,255,0.5);
  --glass-blur: blur(20px);
  --glass-bg-dark: rgba(30,41,59,0.8);
  --glass-border-dark: rgba(255,255,255,0.08);

  /* === GRADIENTS === */
  --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --gradient-secondary: linear-gradient(135deg, #06b6d4 0%, #6366f1 100%);
  --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-card: linear-gradient(145deg, #ffffff 0%, #f8fafc 100%);
  --gradient-success: linear-gradient(135deg, #10b981 0%, #06b6d4 100%);

  /* === TYPOGRAPHY === */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.05em;

  /* === SPACING === */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* === BORDER RADIUS === */
  --radius-sm: 0.375rem;
  --radius-md: 0.625rem;
  --radius-lg: 0.875rem;
  --radius-xl: 1.25rem;
  --radius-2xl: 1.75rem;
  --radius-full: 9999px;

  /* === TRANSITIONS === */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 400ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* === LAYOUT === */
  --sidebar-width: 260px;
  --sidebar-width-sm: 220px;
  --topbar-height: 64px;
  --content-max-width: 1100px;
  --content-padding: var(--space-8);

  /* === Z-INDEX === */
  --z-base: 1;
  --z-above: 10;
  --z-sidebar: 100;
  --z-topbar: 200;
  --z-overlay: 300;
  --z-modal: 400;
  --z-tooltip: 500;
}

/* ============================================
   DARK THEME OVERRIDES
   ============================================ */
[data-theme="dark"] {
  --bg-body: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #263348;
  --bg-sidebar: #1e293b;
  --bg-topbar: rgba(15,23,42,0.95);
  --bg-input: #0f172a;
  --bg-input-focus: #1e293b;
  --bg-overlay: rgba(0,0,0,0.7);

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --border-color: #334155;
  --border-color-strong: #475569;

  --shadow-xs: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.3), 0 2px 4px rgba(0,0,0,0.2);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.4), 0 4px 10px rgba(0,0,0,0.3);
  --shadow-xl: 0 20px 50px rgba(0,0,0,0.5), 0 8px 20px rgba(0,0,0,0.3);
  --shadow-card: 0 4px 24px rgba(0,0,0,0.3);

  --glass-bg: rgba(30,41,59,0.85);
  --glass-border: rgba(255,255,255,0.07);

  --gradient-card: linear-gradient(145deg, #1e293b 0%, #162032 100%);
}