:root {
  --bg-dark: #0a0f1a;
  --bg-card: #111827;
  --bg-card-hover: #1a2234;
  --bg-input: #0d1320;
  --border: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #3b82f6;
  --accent-blue-glow: rgba(59, 130, 246, 0.3);
  --accent-blue-hover: #2563eb;
  --gradient-main: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  --error: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.1);
}

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

body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.login-container {
  width: 100%;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(ellipse at 20% 20%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
              radial-gradient(ellipse at 80% 80%, rgba(139, 92, 246, 0.08) 0%, transparent 50%),
              var(--bg-dark);
  padding: 24px;
}

.login-content {
  width: 100%;
  max-width: 440px;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.login-logo {
  text-align: center;
}

.login-logo h1 {
  font-size: 32px;
  font-weight: 700;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.login-logo span {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 500;
}

.login-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.login-header {
  text-align: center;
  margin-bottom: 32px;
}

.login-header h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.login-header p {
  font-size: 14px;
  color: var(--text-secondary);
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-input {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 16px;
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  transition: all 0.2s ease;
}

.form-input:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px var(--accent-blue-glow);
  background: var(--bg-card);
}

.form-input::placeholder {
  color: var(--text-muted);
}

.form-input:invalid {
  border-color: var(--error);
}

.password-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.password-input-wrapper .form-input {
  padding-right: 48px;
}

.password-toggle {
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: color 0.2s ease;
  border-radius: 6px;
}

.password-toggle:hover {
  color: var(--text-primary);
  background: var(--bg-card-hover);
}

.password-icon {
  font-size: 18px;
  user-select: none;
}

.form-options {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: -4px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
  accent-color: var(--accent-blue);
}

.checkbox-label span {
  user-select: none;
}

.forgot-password-link {
  font-size: 13px;
  color: var(--accent-blue);
  text-decoration: none;
  transition: color 0.2s ease;
}

.forgot-password-link:hover {
  color: var(--accent-blue-hover);
  text-decoration: underline;
}

.btn {
  width: 100%;
  padding: 14px 24px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient-main);
  color: #fff;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.btn-secondary {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--bg-card);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

.btn-icon {
  font-size: 18px;
  transition: transform 0.2s ease;
}

.btn-primary:hover .btn-icon {
  transform: translateX(2px);
}

.login-divider {
  text-align: center;
  margin: 24px 0;
  position: relative;
}

.login-divider::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--border);
}

.login-divider span {
  position: relative;
  background: var(--bg-card);
  padding: 0 16px;
  font-size: 13px;
  color: var(--text-muted);
}

.login-footer {
  text-align: center;
}

.login-footer p {
  font-size: 12px;
  color: var(--text-muted);
}

/* 响应式设计 */
@media (max-width: 480px) {
  .login-card {
    padding: 32px 24px;
  }

  .login-header h2 {
    font-size: 20px;
  }

  .login-logo h1 {
    font-size: 28px;
  }
}

/* 错误状态 */
.form-group.error .form-input {
  border-color: var(--error);
}

.form-group.error .form-error {
  color: var(--error);
  font-size: 12px;
  margin-top: 4px;
}

/* 加载状态 */
.btn-loading {
  position: relative;
  color: transparent;
}

.btn-loading::after {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  top: 50%;
  left: 50%;
  margin-left: -9px;
  margin-top: -9px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spin 0.6s linear infinite;
}

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