body {
        background: linear-gradient(135deg, #f0f4ff, #e6f7ff);
        min-height: 100vh;
        display: flex;
        flex-direction: column;
      }

      /* Карточка авторизации */
      .auth-card {
        max-width: 420px;
        margin: auto;
        padding: 2rem;
        border-radius: 1.5rem;
        background: #fff;
        box-shadow: 0 10px 25px rgba(0,0,0,0.1);
      }

      .auth-card h4 {
        font-weight: 600;
        color: #0d6efd;
      }

      .btn-lab {
        background: linear-gradient(135deg, #4facfe, #00f2fe);
        border: none;
        color: #fff;
        font-weight: 500;
        transition: 0.3s;
      }

      .btn-lab:hover {
        background: linear-gradient(135deg, #00c6ff, #0072ff);
        transform: scale(1.05);
      }

      /* Лого */
      .logo {
        font-size: 1.8rem;
        font-weight: 700;
        color: #0d6efd;
      }