:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #3498db;
  }

  body {
    height: 100vh;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .auth-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
  }

  .auth-header {
    text-align: center;
    margin-bottom: 2rem;
  }

  .auth-header h2 {
    color: var(--primary-color);
    font-weight: 600;
  }

  .form-control {
    border-radius: 8px;
    padding: 0.8rem;
    margin-bottom: 1rem;
  }

  .btn-primary {
    background: var(--primary-color);
    border: none;
    padding: 0.8rem;
    border-radius: 8px;
    width: 100%;
  }

  .btn-primary:hover {
    background: var(--secondary-color);
  }

  .auth-footer {
    text-align: center;
    margin-top: 1.5rem;
  }

  .auth-footer a {
    color: var(--primary-color);
    text-decoration: none;
  }

  .auth-footer a:hover {
    color: var(--secondary-color);
  }

  .form-control:focus {
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
  }