html, body {
            margin: 0;
            padding: 0;
            height: 100%;
            overflow: hidden;
            background: #fff;
        }

        iframe {
            display: none;
            width: 100%;
            height: 100%;
            border: none;
        }

        .loading-container {
            position: fixed;
            width: 100%;
            height: 100%;
            background: white;
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 9999;
        }

        .loading {
            width: 50px;
            height: 50px;
            border: 5px solid #f3f3f3;
            border-top: 5px solid #3498db;
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }