index.html

<!DOCTYPE html>
<html lang="en">

<head>
    <title>Page loading...</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        body {
            display: flex;
            flex-direction: column;
            min-height: 100vh;
            margin: 0;
            justify-content: center;
            align-items: center;
            text-align: center;
            background-color: #f0f0f0;
        }

        #root {
            padding: 20px;
        }

        .loader {
            width: 100px;
            height: 100px;
            border: 16px solid #f3f3f3;
            border-top: 16px solid #3498db;
            border-radius: 50%;
            animation: pulse 1s ease infinite;
        }

        @keyframes pulse {

            0%,
            20% {
                transform: scale(1);
                border-color: #3498db;
            }

            50% {
                transform: scale(1.2);
                border-color: #e74c3c;
            }

            100% {
                transform: scale(1);
                border-color: #2ecc71;
            }
        }

        .error-message {
            font-size: 24px;
            color: #e74c3c;
            font-weight: bold;
            margin-top: 20px;
        }
    </style>
</head>

<body>
    <div id="loader" class="loader"></div>
    <div id="root" style="display: none;"></div>
    <script src="src/bundle.js"></script>
    <script>
        const root = document.getElementById('root');
        const loader = document.getElementById('loader');
        let loadTimeout;

        function hideLoader() {
            loader.style.display = 'none';
            root.style.display = 'block';
            clearTimeout(loadTimeout);
        }

        const observer = new MutationObserver((mutationsList) => {
            for (const mutation of mutationsList) {
                if (mutation.type === 'childList' && root.children.length > 0) {
                    hideLoader();
                    break;
                }
            }
        });

        observer.observe(root, { childList: true });

        // Show an error message if loading takes longer than 5 seconds
        loadTimeout = setTimeout(() => {
            loader.style.display = 'none';
            const errorMessage = document.createElement('div');
            errorMessage.classList.add('error-message');
            errorMessage.innerHTML = 'Error: Loading took too long. Please try refreshing the page or check the URL.';
            root.appendChild(errorMessage);
        }, 5000);
    </script>
</body>

</html>