display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            flex-direction: column;
        }
        
        .spinner {
            border: 4px solid #f3f3f3;
            border-top: 4px solid #409eff;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            animation: spin 1s linear infinite;
            margin-bottom: 20px;
        }
        
        @keyframes spin {
            0% { transform: rotate(