html, body {
            height: 100%;
            margin: 0;
        }

        body {
            display: flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(135deg, #1f1f1f, #3a3a3a);
        }

        .login-card {
            width: 100%;
            max-width: 420px;
            background: #ffffff;
            color: #333;
            border-radius: 15px;
            padding: 40px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.4);
            animation: fadeIn 0.6s ease-in-out;
        }

        .login-card h4 {
            font-size: 32px;
            letter-spacing: 2px;
            margin-bottom: 20px;
            text-align: center;
        }

        .form-control {
            border-radius: 10px;
            padding: 12px;
            transition: 0.3s;
        }

        .form-control:focus {
            border-color: #198754;
            box-shadow: 0 0 0 0.2rem rgba(25,135,84,0.25);
        }

        .btn-custom {
            border-radius: 8px;
            padding: 8px 18px;
            font-size: 14px;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(-15px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }