:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --surface-hover: #243044;
  --border: #2d3a4f;
  --text: #e7ecf3;
  --text-muted: #8b9cb3;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --danger: #ef4444;
  --success: #22c55e;
  --radius: 12px;
  --shadow: 0 24px 48px rgba(0, 0, 0, 0.35);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: radial-gradient(ellipse at top, #1e3a5f 0%, var(--bg) 55%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.container {
  width: 100%;
  max-width: 420px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 28px;
}

.logo {
  text-align: center;
  margin-bottom: 28px;
}

.logo-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), #6366f1);
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 12px;
}

.logo h1 {
  font-size: 20px;
  font-weight: 600;
}

.logo p {
  color: var(--text-muted);
  font-size: 14px;
  margin-top: 6px;
}

.field {
  margin-bottom: 16px;
}

.field label {
  display: block;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.field input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  outline: none;
  transition: border-color 0.2s;
}

.field input:focus {
  border-color: var(--primary);
}

.code-row {
  display: flex;
  gap: 10px;
}

.code-row input {
  flex: 1;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 12px 16px;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, opacity 0.2s;
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

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

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  white-space: nowrap;
  width: auto;
  min-width: 108px;
}

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

.btn-social {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  margin-bottom: 10px;
  gap: 10px;
}

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

.btn-social.wechat {
  border-color: #07c160;
  color: #9ae6b4;
}

.divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  color: var(--text-muted);
  font-size: 13px;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.message {
  padding: 12px 14px;
  border-radius: 8px;
  font-size: 14px;
  margin-bottom: 16px;
  display: none;
}

.message.error {
  display: block;
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(239, 68, 68, 0.35);
  color: #fca5a5;
}

.message.success {
  display: block;
  background: rgba(34, 197, 94, 0.12);
  border: 1px solid rgba(34, 197, 94, 0.35);
  color: #86efac;
}

.loading {
  text-align: center;
  padding: 48px 0;
  color: var(--text-muted);
}

.hp {
  position: absolute;
  left: -9999px;
  opacity: 0;
  height: 0;
  width: 0;
  overflow: hidden;
}

.footer {
  text-align: center;
  margin-top: 20px;
  font-size: 12px;
  color: var(--text-muted);
}

.hidden {
  display: none !important;
}

.spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255, 255, 255, 0.25);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

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

@media (max-width: 480px) {
  .card {
    padding: 24px 20px;
  }
}