/* Dark mode (auto + toggle) */
@media (prefers-color-scheme: dark) {
  body { background:#0f172a; color:#e2e8f0; }
  .card { background:#1e293b; color:#e2e8f0; border-color:#334155; }
  .site-header { background: rgba(15,23,42,.85); border-bottom:1px solid #334155; }
  .site-footer { background: #1e293b; border-top:1px solid #334155; }
  a { color: var(--nc-accent); }
}
body.dark-mode { background:#0f172a; color:#e2e8f0; }
body.dark-mode .card { background:#1e293b; color:#e2e8f0; border-color:#334155; }
body.dark-mode .site-header { background: rgba(15,23,42,.85); border-bottom:1px solid #334155; }
body.dark-mode .site-footer { background:#1e293b; border-top:1px solid #334155; }