:root,[data-theme="k12"]{
  --color-primary:#4A90D9;--color-bg:#F5F7FA;--color-card:#fff;
  --color-text:#2C3E50;--color-muted:#7f8c8d;--color-border:#e0e6ed;
  --answer-red:#E74C3C;--answer-blue:#3498DB;--answer-yellow:#F1C40F;--answer-green:#2ECC71;
  --contact-footer-h:92px;
}
[data-theme="university"]{--color-primary:#2C3E50;--color-bg:#F0F3F6}
[data-theme="dark"]{--color-primary:#1DB954;--color-bg:#1A1A2E;--color-card:#16213E;--color-text:#EAEAEA;--color-muted:#aaa;--color-border:#2a2a4a}
[data-theme="warm"]{--color-primary:#E67E22;--color-bg:#FFF8F0}