roup">
            <select id="cell-type-selector" class="btn" aria-label="Cell type">
                <option value="code">Code</option>
                <option value="markdown">Markdown</option>
                <option value="raw">Raw</option>
            </select>
        </div>
        
        <button class="btn theme-toggle" id="theme-toggle" title="Toggle Theme">
            ðŸŒ“ Theme
        </button>
    </div>
    
    <!-- Notebook Container -->
    <div class="notebook-container">
        