:root {
  color-scheme: light dark;
  --bg: #fafbfc;
  --bg-elev: #ffffff;
  --bg-gradient-a: #f5f3ff;
  --bg-gradient-b: #eef2ff;
  --bg-gradient-c: #fef2f8;
  --fg: #0b1020;
  --fg-muted: #5b6478;
  --fg-subtle: #8a93a6;
  --border: #e6e8ec;
  --border-strong: #d4d8df;
  --primary: #635bff;
  --primary-hover: #564fe0;
  --primary-active: #4842c2;
  --primary-soft: rgba(99, 91, 255, 0.08);
  --primary-ring: rgba(99, 91, 255, 0.25);
  --danger: #c4344b;
  --danger-soft: rgba(196, 52, 75, 0.08);
  --success: #117a4a;
  --success-soft: rgba(17, 122, 74, 0.08);
  --warning: #b25a00;
  --shadow-sm: 0 1px 2px rgba(13, 18, 36, 0.04), 0 1px 1px rgba(13, 18, 36, 0.03);
  --shadow-md: 0 6px 16px rgba(13, 18, 36, 0.06), 0 2px 4px rgba(13, 18, 36, 0.04);
  --shadow-lg: 0 24px 48px -16px rgba(13, 18, 36, 0.18), 0 12px 24px -12px rgba(13, 18, 36, 0.10);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --font-display: 'Inter Tight', Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --ease: cubic-bezier(.2,.6,.3,1);
}

[data-theme='dark'] {
  --bg: #0a0e1a;
  --bg-elev: #11162a;
  --bg-gradient-a: #131a36;
  --bg-gradient-b: #0e1530;
  --bg-gradient-c: #1c1538;
  --fg: #f5f7fb;
  --fg-muted: #aab2c8;
  --fg-subtle: #7a85a0;
  --border: #1e2433;
  --border-strong: #2a3145;
  --primary: #7a73ff;
  --primary-hover: #8d87ff;
  --primary-active: #6660e8;
  --primary-soft: rgba(122, 115, 255, 0.14);
  --primary-ring: rgba(122, 115, 255, 0.35);
  --danger: #f4607a;
  --danger-soft: rgba(244, 96, 122, 0.12);
  --success: #4ade80;
  --success-soft: rgba(74, 222, 128, 0.12);
  --warning: #f0b75a;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 16px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 24px 48px -16px rgba(0, 0, 0, 0.6), 0 12px 24px -12px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  font-feature-settings: 'cv11', 'ss01';
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  background:
    radial-gradient(1200px 600px at -10% -10%, var(--bg-gradient-a), transparent 60%),
    radial-gradient(900px 700px at 110% 10%, var(--bg-gradient-c), transparent 55%),
    radial-gradient(900px 700px at 50% 120%, var(--bg-gradient-b), transparent 60%),
    var(--bg);
  display: flex;
  flex-direction: column;
}

button, input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

.numeric {
  font-variant-numeric: tabular-nums;
}

a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

a:hover {
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:focus-visible {
  outline: none;
  box-shadow: 0 0 0 4px var(--primary-ring);
  border-radius: 4px;
}

/* Layout */
.auth-shell {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 24px;
  min-height: 100vh;
}

.auth-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.auth-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--fg);
}

.auth-brand:hover {
  text-decoration: none;
}

.brand-orb {
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: linear-gradient(135deg, #7a73ff 0%, #635bff 55%, #4842c2 100%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  box-shadow: 0 6px 14px rgba(99, 91, 255, 0.32), inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.theme-toggle {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--fg-muted);
  cursor: pointer;
  transition: background 160ms var(--ease), color 160ms var(--ease), border-color 160ms var(--ease), transform 160ms var(--ease);
}

.theme-toggle:hover {
  color: var(--fg);
  border-color: var(--border-strong);
}

.theme-toggle:active {
  transform: scale(0.96);
}

.theme-toggle:focus-visible {
  outline: none;
  box-shadow: 0 0 0 4px var(--primary-ring);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

.theme-toggle .icon-sun { display: none; }
[data-theme='dark'] .theme-toggle .icon-sun { display: block; }
[data-theme='dark'] .theme-toggle .icon-moon { display: none; }

.auth-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 48px 0 24px;
}

.auth-card {
  width: 100%;
  max-width: 440px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 36px;
  box-shadow: var(--shadow-lg);
  position: relative;
}

.auth-card[data-wide='1'] {
  max-width: 520px;
}

.auth-card-header {
  text-align: center;
  margin-bottom: 24px;
}

.auth-card-header h1 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  font-size: 26px;
  line-height: 1.2;
  margin: 0 0 8px;
  color: var(--fg);
}

.auth-card-header p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 14.5px;
  line-height: 1.5;
}

.invite-meta {
  margin: 12px 0 0;
  padding: 12px 14px;
  background: var(--primary-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 13.5px;
  color: var(--fg);
  text-align: left;
}

.invite-meta strong {
  font-weight: 600;
}

.invite-meta-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 3px 0;
  color: var(--fg-muted);
}

.invite-meta-row span:last-child {
  color: var(--fg);
  font-weight: 500;
}

/* Form */
.auth-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  font-weight: 500;
  color: var(--fg);
  letter-spacing: 0.005em;
}

.field-hint-link {
  font-size: 12.5px;
  font-weight: 500;
}

.field-input {
  appearance: none;
  width: 100%;
  height: 44px;
  padding: 0 14px;
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  font-size: 14.5px;
  color: var(--fg);
  transition: border-color 160ms var(--ease), box-shadow 160ms var(--ease), background 160ms var(--ease);
}

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

.field-input:hover {
  border-color: var(--fg-subtle);
}

.field-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--primary-ring);
}

.field-input[aria-invalid='true'] {
  border-color: var(--danger);
  box-shadow: 0 0 0 4px var(--danger-soft);
}

.field-input:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  background: var(--bg);
}

.field-error {
  font-size: 12.5px;
  color: var(--danger);
  min-height: 1em;
  line-height: 1.4;
}

.field-with-toggle {
  position: relative;
}

.field-with-toggle .field-input {
  padding-right: 44px;
}

.password-toggle {
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 0;
  border-radius: 8px;
  color: var(--fg-subtle);
  cursor: pointer;
  transition: color 160ms var(--ease), background 160ms var(--ease);
}

.password-toggle:hover {
  color: var(--fg);
  background: var(--primary-soft);
}

.password-toggle:focus-visible {
  outline: none;
  color: var(--fg);
  box-shadow: 0 0 0 4px var(--primary-ring);
}

.password-toggle svg {
  width: 18px;
  height: 18px;
}

.password-toggle .icon-eye-off { display: none; }
.password-toggle[data-show='1'] .icon-eye-off { display: block; }
.password-toggle[data-show='1'] .icon-eye { display: none; }

/* Strength meter */
.strength {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 2px;
}

.strength-bars {
  display: flex;
  gap: 4px;
}

.strength-bar {
  flex: 1;
  height: 4px;
  border-radius: 999px;
  background: var(--border);
  transition: background 220ms var(--ease);
}

.strength[data-score='1'] .strength-bar:nth-child(-n+1),
.strength[data-score='2'] .strength-bar:nth-child(-n+2),
.strength[data-score='3'] .strength-bar:nth-child(-n+3),
.strength[data-score='4'] .strength-bar:nth-child(-n+4) {
  background: var(--strength-color, var(--fg-subtle));
}

.strength[data-score='1'] { --strength-color: var(--danger); }
.strength[data-score='2'] { --strength-color: var(--warning); }
.strength[data-score='3'] { --strength-color: #c98b00; }
.strength[data-score='4'] { --strength-color: var(--success); }

.strength-label {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--fg-muted);
}

.strength-label-status {
  color: var(--fg);
  font-weight: 500;
}

/* Buttons */
.btn {
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  height: 44px;
  padding: 0 16px;
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: background 160ms var(--ease), border-color 160ms var(--ease), color 160ms var(--ease), box-shadow 160ms var(--ease), transform 160ms var(--ease);
}

.btn:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 4px var(--primary-ring);
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(99, 91, 255, 0.28), inset 0 1px 0 rgba(255, 255, 255, 0.16);
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-hover);
}

.btn-primary:active:not(:disabled) {
  background: var(--primary-active);
  transform: translateY(1px);
}

.btn-block {
  width: 100%;
}

.btn-secondary {
  background: var(--bg-elev);
  color: var(--fg);
  border-color: var(--border-strong);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--fg-subtle);
  background: var(--primary-soft);
}

.btn-spinner {
  display: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid currentColor;
  border-top-color: transparent;
  animation: btn-spin 720ms linear infinite;
}

.btn[data-loading='1'] .btn-spinner {
  display: inline-block;
}

.btn[data-loading='1'] .btn-label {
  opacity: 0.7;
}

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

@media (prefers-reduced-motion: reduce) {
  .btn-spinner { animation-duration: 1500ms; }
  *, *::before, *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}

.captcha-mount {
  display: flex;
  justify-content: center;
  min-height: 65px;
}

.captcha-mount:empty::before {
  content: '';
  display: block;
  width: 300px;
  height: 65px;
  background: linear-gradient(90deg, var(--bg-elev) 0%, var(--primary-soft) 50%, var(--bg-elev) 100%);
  background-size: 200% 100%;
  animation: skeleton 1400ms var(--ease) infinite;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

@keyframes skeleton {
  to { background-position: -200% 0; }
}

/* Footer / sub-links */
.auth-footer {
  margin-top: 22px;
  text-align: center;
  font-size: 13.5px;
  color: var(--fg-muted);
}

.auth-footer .sep {
  margin: 0 6px;
  color: var(--border-strong);
}

.auth-bottom {
  text-align: center;
  font-size: 12px;
  color: var(--fg-subtle);
  margin-top: 24px;
  padding-bottom: 4px;
}

/* Form alerts */
.form-alert {
  display: none;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  font-size: 13.5px;
  line-height: 1.5;
  border: 1px solid transparent;
}

.form-alert[data-kind='error'] {
  display: flex;
  background: var(--danger-soft);
  color: var(--danger);
  border-color: var(--danger);
}

.form-alert[data-kind='success'] {
  display: flex;
  background: var(--success-soft);
  color: var(--success);
  border-color: var(--success);
}

.form-alert[data-kind='info'] {
  display: flex;
  background: var(--primary-soft);
  color: var(--fg);
  border-color: var(--border-strong);
}

.form-alert svg {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  margin-top: 1px;
}

/* Success / informational screens */
.auth-state {
  text-align: center;
}

.auth-state-icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-soft);
  color: var(--primary);
  margin-bottom: 16px;
}

.auth-state-icon svg {
  width: 28px;
  height: 28px;
}

.auth-state-icon[data-kind='success'] {
  background: var(--success-soft);
  color: var(--success);
}

.auth-state-icon[data-kind='warn'] {
  background: var(--danger-soft);
  color: var(--danger);
}

.auth-state h2 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  font-size: 20px;
  margin: 0 0 8px;
  color: var(--fg);
}

.auth-state p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 14px;
  line-height: 1.5;
}

.auth-state p + p {
  margin-top: 8px;
}

.auth-state .btn {
  margin-top: 20px;
}

/* Toasts */
.toast-region {
  position: fixed;
  right: 20px;
  bottom: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 60;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  min-width: 260px;
  max-width: 360px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 13.5px;
  color: var(--fg);
  transform: translateY(8px);
  opacity: 0;
  transition: opacity 200ms var(--ease), transform 200ms var(--ease);
}

.toast[data-visible='1'] {
  opacity: 1;
  transform: translateY(0);
}

.toast[data-kind='error'] { border-color: var(--danger); }
.toast[data-kind='success'] { border-color: var(--success); }

.toast-icon {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  margin-top: 1px;
}

.toast[data-kind='error'] .toast-icon { color: var(--danger); }
.toast[data-kind='success'] .toast-icon { color: var(--success); }
.toast[data-kind='info'] .toast-icon { color: var(--primary); }

.toast-body { flex: 1; line-height: 1.45; }

.toast-close {
  background: transparent;
  border: 0;
  color: var(--fg-subtle);
  cursor: pointer;
  padding: 0;
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.toast-close:hover { color: var(--fg); }

.toast-close svg { width: 14px; height: 14px; }

/* Skeleton block (invite lookup) */
.skeleton {
  background: linear-gradient(90deg, var(--bg-elev) 0%, var(--primary-soft) 50%, var(--bg-elev) 100%);
  background-size: 200% 100%;
  animation: skeleton 1400ms var(--ease) infinite;
  border-radius: var(--radius-md);
}

.skeleton-line {
  height: 12px;
  margin: 6px 0;
}

.hidden { display: none !important; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* Mobile */
@media (max-width: 640px) {
  .auth-shell { padding: 16px; }
  .auth-card { padding: 24px 20px; border-radius: var(--radius-lg); }
  .auth-main { padding: 24px 0; }
  .auth-card-header h1 { font-size: 22px; }
  .toast-region { left: 16px; right: 16px; bottom: 16px; }
  .toast { max-width: none; }
}

@media (max-width: 380px) {
  .auth-shell { padding: 12px; }
}