Accordion / 023 — 左カスケード

デザイン見本

Left to right slide cascade
Items slide in from left
Dynamic slide effect

リスト項目が左から順にスライドインするカスケードアニメーション。横方向の動きを加えることで、動的でスタイリッシュな印象を与えます。

実装コード

HTML

<div class="container">
    <div class="btn-box">
        <button data-default-text="Simple Cascade Left Accordion" data-open-text="Close">Simple Cascade Left Accordion</button>
    </div>
    <div class="more">
        <ul>
            <li>Left to right slide cascade</li>
            <li>Items slide in from left</li>
            <li>Dynamic slide effect</li>
        </ul>
    </div>
</div>

CSS

.container {
    width: 100%;
    margin-bottom: 0;
}

.container .btn-box button {
    width: 100%;
    padding: 14px 0;
    background: transparent;
    border: none;
    font-size: 14px;
    font-weight: 400;
    color: #333;
    cursor: pointer;
    transition: all 0.3s;
    text-align: left;
    position: relative;
}

.container .btn-box button::after {
    content: '▼';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    font-size: 18px;
    color: #666;
    transition: all 0.3s;
}

.container .btn-box button:hover {
    color: #000;
}

.container .more {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    background: transparent;
}

.container .more.appear {
    max-height: 200px;
}

.container:has(.more.appear) .btn-box button::after {
    content: '▲';
    color: #000;
}

.container .more ul {
    list-style: none;
    padding: 10px 0;
    margin: 0;
}

.container .more li {
    padding: 6px 0;
    color: #666;
    font-size: 13px;
    opacity: 0;
    transform: translateX(-30px);
    transition: all 0.4s ease;
}

.container .more.appear li {
    opacity: 1;
    transform: translateX(0);
}

.container .more.appear li:nth-child(1) {
    transition-delay: 0.1s;
}

.container .more.appear li:nth-child(2) {
    transition-delay: 0.2s;
}

.container .more.appear li:nth-child(3) {
    transition-delay: 0.3s;
}

document.addEventListener("DOMContentLoaded", () => {
    document.querySelectorAll('.container').forEach(container => {
        const button = container.querySelector('.btn-box button');
        const content = container.querySelector('.more');
        
        if (button && content) {
            button.addEventListener('click', function() {
                content.classList.toggle('appear');
                
                // ボタンテキストの切り替え
                if (content.classList.contains('appear')) {
                    this.textContent = this.dataset.openText || 'Close';
                } else {
                    this.textContent = this.dataset.defaultText;
                }
            });
        }
    });
});