ハンバーガーメニュー：ドットメニュー｜Hamburger Menu: Dot Grid

<div class="container">
    <div class="hamburger-menu">
        <div class="dot-row">
            <div class="dot"></div>
            <div class="dot"></div>
            <div class="dot"></div>
        </div>
        <div class="dot-row">
            <div class="dot"></div>
            <div class="dot"></div>
            <div class="dot"></div>
        </div>
        <div class="dot-row">
            <div class="dot"></div>
            <div class="dot"></div>
            <div class="dot"></div>
        </div>
        <div class="close-icon"></div>
    </div>
    <nav class="nav-menu">
        <a href="#">Menu 1</a>
        <a href="#">Menu 2</a>
        <a href="#">Menu 3</a>
        <a href="#">Menu 4</a>
        <a href="#">Menu 5</a>
        <a href="#">Menu 6</a>
        <a href="#">Menu 7</a>
        <a href="#">Menu 8</a>
        <a href="#">Menu 9</a>
        <a href="#">Menu 10</a>
    </nav>
</div>

.container {
    position: relative;
    width: 100%;
    height: 300px;
    margin-top: 20px;
}

.hamburger-menu {
    width: 30px;
    height: 30px;
    position: absolute;
    top: 20px;
    right: 20px;
    cursor: pointer;
    user-select: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.dot-row {
    display: flex;
    justify-content: space-between;
    width: 100%;
    transition: all 0.3s ease;
}

.dot {
    background-color: black;
    transition: all 0.3s;
    width: 4px;
    height: 4px;
    border-radius: 1px;
}

.hamburger-menu.active .dot-row {
    opacity: 0;
    transform: scale(0.8);
}

.close-icon {
    display: block;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    width: 30px;
    height: 4px;
    opacity: 0;
    transition: all 0.3s ease;
}

.close-icon::before,
.close-icon::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 30px;
    height: 4px;
    background-color: black;
    transform-origin: center;
}

.close-icon::before {
    transform: translate(-50%, -50%) rotate(45deg);
}

.close-icon::after {
    transform: translate(-50%, -50%) rotate(-45deg);
}

.hamburger-menu.active .close-icon {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
}

.nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 45%;
    left: 50%;
    transform: translate(-50%, -50%);
    align-items: center;
    justify-content: flex-start;
    padding: 8px;
    width: 50%;
    background-color: #fff;
    border: 1px solid #ccc;
    opacity: 0;
    overflow-y: auto;
    overflow-x: hidden;
    box-sizing: border-box;
    max-height: 80%;
}

.nav-menu.active {
    display: flex;
    animation: fadeIn 0.5s forwards;
}

.nav-menu a {
    text-decoration: none;
    color: black;
    padding: 5px;
    margin: 5px;
}

@keyframes fadeIn {
    0% {
        top: 45%;
        opacity: 0;
    }
    
    100% {
        top: 50%;
        opacity: 1;
    }
}

// すべてのハンバーガーメニューにイベントリスナーを追加
document.querySelectorAll('.hamburger-menu').forEach(function(menu) {
    menu.addEventListener('click', function() {
        this.classList.toggle('active');
        // 同じコンテナ内のnav-menuを取得
        const navMenu = this.parentElement.querySelector('.nav-menu');
        if (navMenu) {
            navMenu.classList.toggle('active');
        }
    });
});