:root,
[data-theme="light"] {
  --bg-app: #f4f7fb;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-surface-muted: #eef2f8;
  --bg-surface-hover: #e5ebf5;
  --bg-glass: rgba(255, 255, 255, 0.88);
  --bg-backdrop: rgba(15, 23, 42, 0.55);

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #ffffff;

  --brand-primary: #2563eb;
  --brand-primary-hover: #1d4ed8;
  --brand-primary-soft: rgba(37, 99, 235, 0.12);
  --brand-secondary: #0d9488;
  --brand-secondary-hover: #0f766e;
  --brand-secondary-soft: rgba(13, 148, 136, 0.12);

  --color-success: #16a34a;
  --color-success-soft: rgba(22, 163, 74, 0.14);
  --color-warning: #d97706;
  --color-warning-soft: rgba(217, 119, 6, 0.14);
  --color-danger: #dc2626;
  --color-danger-soft: rgba(220, 38, 38, 0.14);
  --color-info: #0284c7;
  --color-info-soft: rgba(2, 132, 199, 0.14);
  --color-xp: #7c3aed;
  --color-xp-soft: rgba(124, 58, 237, 0.13);
  --color-streak: #ea580c;
  --color-streak-soft: rgba(234, 88, 12, 0.14);

  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.35);

  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 2px 6px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 16px 36px rgba(15, 23, 42, 0.12);

  --sidebar-width: 268px;
  --topbar-height: 68px;
  --mobile-nav-height: 68px;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 22px;
  --radius-full: 9999px;

  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 240ms cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-app: #0b1120;
  --bg-surface: #131c31;
  --bg-surface-elevated: #1b2640;
  --bg-surface-muted: #18233c;
  --bg-surface-hover: #223052;
  --bg-glass: rgba(19, 28, 49, 0.9);
  --bg-backdrop: rgba(2, 6, 23, 0.75);

  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-inverse: #0f172a;

  --brand-primary: #3b82f6;
  --brand-primary-hover: #60a5fa;
  --brand-primary-soft: rgba(59, 130, 246, 0.18);
  --brand-secondary: #14b8a6;
  --brand-secondary-hover: #2dd4bf;
  --brand-secondary-soft: rgba(20, 184, 166, 0.18);

  --color-success: #22c55e;
  --color-success-soft: rgba(34, 197, 94, 0.18);
  --color-warning: #f59e0b;
  --color-warning-soft: rgba(245, 158, 11, 0.18);
  --color-danger: #ef4444;
  --color-danger-soft: rgba(239, 68, 68, 0.18);
  --color-info: #38bdf8;
  --color-info-soft: rgba(56, 189, 248, 0.18);
  --color-xp: #a78bfa;
  --color-xp-soft: rgba(167, 139, 250, 0.18);
  --color-streak: #fb923c;
  --color-streak-soft: rgba(251, 146, 60, 0.18);

  --border-subtle: #1e293b;
  --border-strong: #334155;
  --focus-ring: 0 0 0 3px rgba(59, 130, 246, 0.45);

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.25);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 10px 26px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 18px 40px rgba(0, 0, 0, 0.6);
}