body {
            background: linear-gradient(135deg, #2c3e50, #34495e);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
        }
.login-card {
            width: 100%;
            max-width: 450px;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
        }
.alert {
            border-radius: 10px;
        }
.btn-link {
            text-decoration: none;
            font-size: 0.9rem;
        }
.code-input {
            letter-spacing: 5px;
            font-size: 24px;
            text-align: center;
        }