タブメニュー：ハイライト｜Tab Menu: Highlight

<div class="tab-container">
    <ul>
        <li class="selected" data-id="tab-1">Tab 1</li>
        <li data-id="tab-2">Tab 2</li>
        <li data-id="tab-3">Tab 3</li>
    </ul>
    <div class="tab-content selected" id="tab-1">Good morning. This is the content of Tab 1.</div>
    <div class="tab-content" id="tab-2">Hello. This is the content of Tab 2.</div>
    <div class="tab-content" id="tab-3">Good evening. This is the content of Tab 3.</div>
</div>

.tab-container ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    border-bottom: none;
}

.tab-container ul li {
    flex: 1;
    padding: 16px 24px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    color: #999;
    font-weight: 300;
    letter-spacing: 0.5px;
}

.tab-container ul li.selected { 
    color: #333; 
    font-weight: 500; 
    background-color: #f0f0f0; 
}

.tab-container ul li:not(.selected):hover { 
    color: #333; 
    background: #fafafa; 
}

.tab-content { 
    display: none; 
    padding: 32px 24px; 
    min-height: 150px; 
    color: #333; 
    line-height: 1.6; 
}

.tab-content.selected { 
    display: block; 
    animation: fadeIn 0.3s ease; 
}

@keyframes fadeIn { 
    from { opacity: 0; transform: translateY(10px); } 
    to { opacity: 1; transform: translateY(0); } 
}

const tabContainers = document.querySelectorAll('.tab-container');
tabContainers.forEach(container => {
    const tabMenuItems = container.querySelectorAll('ul li');
    const tabContents = container.querySelectorAll('.tab-content');
    tabMenuItems.forEach(tabMenuItem => {
        tabMenuItem.addEventListener('click', () => {
            tabMenuItems.forEach(item => item.classList.remove('selected'));
            tabMenuItem.classList.add('selected');
            tabContents.forEach(tabContent => tabContent.classList.remove('selected'));
            document.getElementById(tabMenuItem.dataset.id).classList.add('selected');
        });
    });
});