.login-rail {
  position: fixed;
  width: 100%;
}

.theme-toggle {
  position: relative;
  overflow: hidden;
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  margin-left: auto;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--surface-container-high);
  color: var(--on-surface-variant);
  font: 20px/1 var(--font);
  cursor: pointer;
}

.theme-toggle::after {
  content: "";
  position: absolute;
  inset: 0;
  background: currentColor;
  opacity: 0;
  transition: opacity 0.15s ease;
  pointer-events: none;
}

.theme-toggle:hover::after { opacity: 0.08; }
.theme-toggle:active::after { opacity: 0.12; }
.theme-toggle:focus-visible { outline: 3px solid var(--primary); outline-offset: 2px; }

.login-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 88px var(--s6) var(--s6);
}

.login-panel {
  width: calc(100vw - 48px);
  max-width: 420px;
  min-width: 0;
  padding: var(--s6);
  border: 1px solid var(--outline-variant);
  border-radius: var(--radius-xs);
  background: var(--surface-container-low);
  box-shadow: var(--elev-3);
}

.login-heading {
  display: flex;
  align-items: center;
  gap: var(--s4);
  margin-bottom: var(--s6);
}

.login-logo {
  width: 56px;
  height: 56px;
  flex: 0 0 auto;
}

.login-heading h1 {
  margin: 0;
  color: var(--on-surface);
  font-family: var(--font-display);
  font-size: var(--t-xl);
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: 0;
}

.login-heading p {
  margin: var(--s1) 0 0;
  color: var(--on-surface-variant);
  font-size: var(--t-sm);
}

.login-panel .field { margin-bottom: var(--s4); }

.login-panel form,
.login-panel .field,
.login-panel .field input {
  min-width: 0;
}

.login-panel .field input {
  min-height: 48px;
  letter-spacing: 0;
}

.error {
  margin: 0 0 var(--s4);
  padding: var(--s3);
  border-radius: var(--radius-xs);
  background: var(--danger-container);
  color: var(--danger);
  font-size: var(--t-sm);
}

.login-submit {
  width: 100%;
  min-height: 44px;
}

.login-submit:disabled {
  cursor: wait;
}

@media (max-width: 480px) {
  .login-shell { padding: 80px var(--s4) var(--s4); }
  .login-panel { width: calc(100vw - 32px); padding: var(--s4); }
}