:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --border: #2d3a4f;
  --text: #e8edf4;
  --muted: #8b9cb3;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --success: #22c55e;
  --error-bg: rgba(239, 68, 68, 0.12);
  --error-text: #fca5a5;
  --success-bg: rgba(34, 197, 94, 0.12);
  --success-text: #86efac;
  --radius: 14px;
  --shadow: 0 24px 48px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(59, 130, 246, 0.18), transparent),
    var(--bg);
  color: var(--text);
}

.page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card {
  width: 100%;
  max-width: 420px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
}

.hidden {
  display: none !important;
}

.brand {
  display: flex;
  gap: 16px;
  align-items: center;
  margin-bottom: 28px;
}

.brand-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--primary), #6366f1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 20px;
  flex-shrink: 0;
}

.brand-icon.success {
  background: linear-gradient(135deg, var(--success), #16a34a);
}

h1 {
  margin: 0 0 4px;
  font-size: 1.5rem;
  font-weight: 600;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  padding: 4px;
  background: rgba(0, 0, 0, 0.25);
  border-radius: 10px;
  margin-bottom: 24px;
}

.tab {
  border: none;
  background: transparent;
  color: var(--muted);
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.tab:hover {
  color: var(--text);
}

.tab.active {
  background: var(--primary);
  color: white;
}

.form {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

label {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
}

input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.2);
  color: var(--text);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

input::placeholder {
  color: #5a6b82;
}

.btn {
  border: none;
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, opacity 0.15s;
}

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

.btn.primary {
  background: var(--primary);
  color: white;
  margin-top: 4px;
}

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

.btn.secondary {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  width: 100%;
}

.btn.secondary:hover {
  color: var(--text);
  border-color: var(--muted);
}

.message {
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 0.875rem;
  margin-bottom: 18px;
}

.message.error {
  background: var(--error-bg);
  color: var(--error-text);
  border: 1px solid rgba(239, 68, 68, 0.25);
}

.message.success {
  background: var(--success-bg);
  color: var(--success-text);
  border: 1px solid rgba(34, 197, 94, 0.25);
}

.user-info {
  margin: 0 0 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.user-info > div {
  padding: 14px 16px;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.user-info dt {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 4px;
}

.user-info dd {
  margin: 0;
  font-size: 1rem;
  word-break: break-all;
}