:root {
      --color-primary: #bc0606; /* Rojo corporativo */
      --color-dark: #212529;
      --color-white: #ffffff;
    }
    body {
      background-color: #f8f9fa;
      font-family: 'Segoe UI', system-ui, sans-serif;
    }
    .card {
      border: none;
      border-radius: 16px;
      box-shadow: 0 0.75rem 2rem rgba(0, 0, 0, 0.12);
      background: var(--color-white);
    }
    .btn-primary-custom {
      background-color: var(--color-primary);
      border-color: var(--color-primary);
      color: white;
      font-weight: 600;
    }
    .btn-primary-custom:hover {
      background-color: #9a0505;
      border-color: #9a0505;
      transform: translateY(-2px);
      box-shadow: 0 4px 8px rgba(188, 6, 6, 0.3);
    }
    .logo {
      max-height: 80px;
      margin-bottom: 1.25rem;
    }
    .card-title {
      color: var(--color-primary);
      font-weight: 700;
    }
    .form-control {
      text-align: center;
      padding: 0.75rem;
      font-size: 1.1rem;
    }
    .footer-text {
      font-size: 0.875rem;
      color: #6c757d;
    }