ハンバーガーメニューのスタンダード(CSSとJS)

はじめまして。タクと申します。
現在スクールでフロントエンド分野を学んでいます。

今回が初投稿です。よろしくお願いいたします。
最初はスクールの課題で作成したhtmlサイトのCSSとJavaScritを使用したシンプルなハンバーガーメニューのコードになります。

レスポンシブデザインの定番ですね。

CSS

/* ヘッダー
------------------------------- */
nav {
    position: fixed;
    top: 0;
    right: -100%;
    bottom: 0;
    left: 100%;
    background-color: rgba(255, 255, 255, 0.85);
    transition: all 0.3s ease-in-out;
}

.open nav {
    translate: -100% 0;
}

.main-nav {
    /* background-color: pink; */
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 2.5rem;
    list-style: none;
    text-align: center;
    height: 100%;
}

.main-nav a {
    font-size: 2rem;
    color: dimgrey;
    font-weight: bold;
    display: block;
}

.main-nav a:hover {
    color: #0bd;
}

.nav-btn {
    position: fixed;
    top: 17px;
    right: 20px;
    /* background-color: pink; */
    width: 44px;
    height: 44px;
    padding: 8px;
    background-color: beige;
    border-radius: 22px;
}

.nav-btn-line {
    display: block;
    height: 1px;
    width: 30px;
    background-color: #432;
    position: relative;
    margin: auto;
    transition: all 0.3s ease-in-out;
}

.open .nav-btn-line {
    background-color: transparent;
}

.nav-btn-line::before,
.nav-btn-line::after {
    content: '';
    display: block;
    height: 100%;
    width: 100%;
    background-color: #432;
    position: absolute;
    transition: inherit;
    /* inherit...先祖要素から値を継承 */
}

.nav-btn-line::before {
    top: -10px;
}

.open .nav-btn-line::before {
    rotate: 45deg;
    top:0
}

.nav-btn-line::after {
    top: 10px;
}

.open .nav-btn-line::after {
    rotate: -45deg;
    top: 0;
}


.visually-hidden {
    position: fixed !important;
    /* keep it on viewport */
    top: 0px !important;
    left: 0px !important;
    /* give it non-zero size, VoiceOver on Safari requires at least 2 pixels
     before allowing buttons to be activated. */
    width: 4px !important;
    height: 4px !important;
    /* visually hide it with overflow and opacity */
    opacity: 0 !important;
    overflow: hidden !important;
    /* remove any margin or padding */
    border: none !important;
    margin: 0 !important;
    padding: 0 !important;
    /* ensure no other style sets display to none */
    display: block !important;
    visibility: visible !important;
}

Javascript

const navBtn = document.getElementById('nav-btn');
const bodyElm = document.querySelector('body');
navBtn.addEventListener('click', () => {
bodyElm.classList.toggle('open');
});

const navElm = document.querySelector('nav');
navElm.addEventListener('click', (event) => {
console.log(event.target.href);
if (event.target.href) {
bodyElm.classList.remove('open');
}
});

HTML

<header class="header wrapper">
    <h1 class="header-logo">
        <a href="index.html"><img src="images/header-logo.png" alt=""></a>
    </h1>
    <nav>
        <ul class="main-nav">
        <li><a href="index.html#works">Works</a></li>
        <li><a href="index.html#about">About</a></li>
        </ul>
    </nav>

    <button type="button" class="nav-btn" id="nav-btn">
        <span class="nav-btn-line">
        <span class="visually-hidden">メニュー開閉</span>
        </span>
    </button>
</header>