.auth-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
}
.auth-head .brand {
  margin: 0;
  justify-content: flex-start;
}
.auth-theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  height: 36px;
  padding: 0 9px;
  border: 1px solid #d9dde4;
  border-radius: 9px;
  background: #fff;
  color: #111;
  font: 700 11px/1 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  cursor: pointer;
}
.auth-theme-track {
  position: relative;
  width: 32px;
  height: 18px;
  border-radius: 99px;
  background: #d4d4d8;
  transition: .18s;
}
.auth-theme-track span {
  position: absolute;
  left: 2px;
  top: 2px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, .25);
  transition: .18s;
}
.auth-theme-toggle[aria-checked="true"] .auth-theme-track { background: #f59e0b; }
.auth-theme-toggle[aria-checked="true"] .auth-theme-track span { transform: translateX(14px); }
html[data-theme="dark"] {
  color-scheme: dark;
  --ink: #f8fafc;
  --muted: #b3bdca;
  --line: #394452;
  --border: #394452;
  --surface: #15191f;
  --canvas: #0b0e12;
}
html[data-theme="dark"] body { background: #0b0e12; color: #f8fafc; }
html[data-theme="dark"] .login-card,
html[data-theme="dark"] .card {
  background: #15191f;
  border-color: #394452;
  box-shadow: 0 12px 32px rgba(0, 0, 0, .3);
}
html[data-theme="dark"] .field label,
html[data-theme="dark"] h1,
html[data-theme="dark"] .brand { color: #f8fafc; }
html[data-theme="dark"] .field input,
html[data-theme="dark"] .field select {
  background: #0e1217;
  color: #f8fafc;
  border-color: #465363;
}
html[data-theme="dark"] .field input::placeholder { color: #8490a0; }
html[data-theme="dark"] .password-toggle { background: #292d33; color: #e5e7eb; }
html[data-theme="dark"] .password-toggle:hover { background: #343840; }
html[data-theme="dark"] .auth-theme-toggle { background: #1b1e22; color: #f4f4f5; border-color: #393e46; }
html[data-theme="dark"] .plan-option span { background: #15191f; border-color: #394452; }
html[data-theme="dark"] .plan-option input:checked + span {
  background: #202832;
  border-color: #8ca0b8;
  box-shadow: 0 0 0 3px rgba(140, 160, 184, .15);
}
html[data-theme="dark"] .plan-option strong { color: #f8fafc; }
html[data-theme="dark"] .plan-saving em { color: #fbbf24; }
html[data-theme="dark"] .payment-box { background: #17231e; border-color: #315443; }
html[data-theme="dark"] .payment-box h2 { color: #f8fafc; }
html[data-theme="dark"] .proof-upload { background: #11161c; border-color: #526174; }
html[data-theme="dark"] .proof-upload.has-file { background: #17231e; border-color: #4b8c68; }
html[data-theme="dark"] .button.secondary { background: #292d33; color: #f4f4f5; }
html[data-theme="dark"] .register-submit { background: #f4f4f5; color: #111; }
html[data-theme="dark"] .register-submit:hover { background: #d4d4d8; }
html[data-theme="dark"] .workspace-info { background: #f4f4f5; color: #111; }
html[data-theme="dark"] .help a { color: #f4f4f5; }
@media (max-width: 480px) {
  .auth-head { margin-bottom: 18px; }
  .auth-theme-toggle [data-theme-label] { display: none; }
}