lock" aria-hidden="true"></i>
                <h1>ChronoSphere</h1>
            </div>
            <div class="header-controls">
                <button class="mode-switch" id="mode-switch" aria-label="Toggle dark mode">Dark Mode</button>
            </div>
        </header>

        <nav class="tab-navigation" role="navigation" aria-label="Clock functions">
            <button class="tab-btn active" data-tab="analog-clock" aria-selected="true" aria-controls="analog-clock">
                <i class="fas fa-