*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  color-scheme: light;

  --z-surface: #f4f6f9;
  --z-surface-raised: #ffffff;
  --z-surface-sunken: #ebedf2;
  --z-border: #e2e6ee;
  --z-border-strong: #cdd3df;
  --z-fg: #1a2332;
  --z-fg-muted: #5c677a;
  --z-fg-subtle: #8b95a5;
  --z-accent: #2563eb;
  --z-accent-hover: #1d4ed8;
  --z-accent-fg: #ffffff;
  --z-success: #16a34a;
  --z-warning: #d97706;
  --z-danger: #dc2626;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --header-height: 3.25rem;
  --shadow-sm: 0 1px 2px rgb(15 23 42 / 0.04);
  --shadow-md: 0 4px 12px rgb(15 23 42 / 0.06);

  /* Tachyons Neo Variables Override (Light Mode) */
  --near-white: var(--z-surface);
  --white: var(--z-surface-raised);
  --near-black: var(--z-fg);
  --mid-gray: var(--z-fg-muted);
  --gray: var(--z-fg-subtle);
  --light-gray: var(--z-border);
  --moon-gray: var(--z-border-strong);
  --blue: var(--z-accent);
  --dark-blue: var(--z-accent-hover);
  --green: var(--z-success);
  --orange: var(--z-warning);
  --red: var(--z-danger);
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;

    --z-surface: #0f1419;
    --z-surface-raised: #171d26;
    --z-surface-sunken: #0a0e13;
    --z-border: #252d3a;
    --z-border-strong: #343f50;
    --z-fg: #e8edf5;
    --z-fg-muted: #9aa5b8;
    --z-fg-subtle: #6b778a;
    --z-accent: #3b82f6;
    --z-accent-hover: #2563eb;

    /* Tachyons Neo Variables Override (Dark Mode) */
    --near-white: var(--z-surface);
    --white: var(--z-surface-raised);
    --near-black: var(--z-fg);
    --mid-gray: var(--z-fg-muted);
    --gray: var(--z-fg-subtle);
    --light-gray: var(--z-border);
    --moon-gray: var(--z-border-strong);
    --blue: var(--z-accent);
    --dark-blue: var(--z-accent-hover);
  }
}

html {
  scroll-behavior: smooth;
}

body {
  -webkit-font-smoothing: antialiased;
}

.container {
  width: min(1100px, 92vw);
  margin: 0 auto;
}

.logo {
  font-size: 1.125rem;
  font-weight: 800;
  letter-spacing: -0.04em;
}

.site-header {
  height: var(--header-height);
}

.tool-link {
  transition: background 0.15s, color 0.15s;
}

.tool-link:hover,
.tool-link.is-active {
  background: var(--z-surface-sunken);
}

.z-input {
  transition: border-color 0.15s, box-shadow 0.15s;
}

.z-input:hover {
  border-color: var(--z-border-strong);
}

.z-input:focus {
  outline: none;
  border-color: var(--z-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--z-accent) 20%, transparent);
}

.z-input::placeholder {
  color: var(--z-fg-subtle);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s, transform 0.1s ease-out;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--z-accent);
  color: var(--z-accent-fg);
}

.btn-primary:hover {
  background: var(--z-accent-hover);
  color: var(--z-accent-fg);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-ghost {
  background: transparent;
  color: var(--z-fg-muted);
  border: 1px solid var(--z-border);
}

.btn-ghost:hover {
  background: var(--z-surface-sunken);
  color: var(--z-fg);
}

.btn-danger {
  background: color-mix(in srgb, var(--z-danger) 12%, transparent);
  color: var(--z-danger);
  border: 1px solid color-mix(in srgb, var(--z-danger) 30%, transparent);
}

.btn-danger:hover {
  background: var(--z-danger);
  color: #fff;
  border-color: var(--z-danger);
}

.validation-hint {
  min-height: 1.25rem;
}

.result-row {
  transition: background 0.15s;
}

.result-row.available:hover {
  background: var(--z-surface-sunken);
}

.result-row.selected {
  background: color-mix(in srgb, var(--z-accent) 8%, var(--z-surface-raised));
  box-shadow: inset 3px 0 0 var(--z-accent);
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid var(--z-border);
  border-top-color: var(--z-accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.btn-register {
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  border: none;
  background: var(--z-accent);
  color: var(--z-accent-fg);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
}

.btn-register:hover {
  background: var(--z-accent-hover);
}

.register-panel {
  display: none;
}

.register-panel.visible {
  display: block;
}

.strength-bar {
  height: 4px;
  background: var(--z-border);
  border-radius: 999px;
  margin-top: 0.5rem;
  overflow: hidden;
}

.strength-fill {
  height: 100%;
  border-radius: 999px;
  transition: width 0.3s, background 0.3s;
  width: 0;
}

.strength-label {
  font-size: 0.75rem;
  color: var(--z-fg-subtle);
  margin-top: 0.25rem;
}

.notification {
  padding: 0.75rem 0.875rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  margin-bottom: 1rem;
  display: none;
}

.notification.error {
  display: block;
  background: color-mix(in srgb, var(--z-danger) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--z-danger) 25%, transparent);
  color: var(--z-danger);
}

.notification.success {
  display: block;
  background: color-mix(in srgb, var(--z-success) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--z-success) 25%, transparent);
  color: var(--z-success);
}

.success-icon {
  font-size: 1.75rem;
  font-weight: 700;
}

.dashboard-container {
  animation: fadeIn 0.35s ease-out;
}

.invites-table th,
.invites-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--z-border);
}

.invites-table tbody tr:hover {
  background: var(--z-surface-sunken);
}

.invites-table tbody tr:last-child td {
  border-bottom: none;
}

.td-code {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: ui-monospace, monospace;
  font-size: 0.875rem;
}

.code-text {
  font-weight: 600;
}

.btn-copy {
  background: none;
  border: none;
  padding: 0.25rem;
  cursor: pointer;
  border-radius: var(--radius-sm);
  color: var(--z-fg-subtle);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-copy:hover {
  color: var(--z-fg);
  background: var(--z-surface-sunken);
}

.icon-copy {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.btn-copy.copied {
  color: var(--z-success);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-size: 0.6875rem;
  font-weight: 600;
  border: 1px solid color-mix(in srgb, currentColor 24%, transparent);
  line-height: 1;
}

.badge::before {
  content: '';
  display: inline-block;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  margin-right: 0.35rem;
  background-color: currentColor;
}

.badge-unused {
  background: color-mix(in srgb, var(--z-success) 12%, transparent);
  color: var(--z-success);
}

.badge-used {
  background: color-mix(in srgb, var(--z-warning) 12%, transparent);
  color: var(--z-warning);
}

.badge-revoked {
  background: color-mix(in srgb, var(--z-danger) 12%, transparent);
  color: var(--z-danger);
}

.badge-pending {
  background: color-mix(in srgb, var(--z-accent) 12%, transparent);
  color: var(--z-accent);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}