const product = document.querySelector('.product');
console.log(product.dataset.price); // 输出: 29.99
console.log(product.dataset.inStock); // 注意驼峰命名：in-stock → inStock

<button class="like-btn" data-liked="false" onclick="toggleLike(this)">? 赞</button>

function toggleLike(btn) {
  const isLiked = btn.dataset.liked === 'true';
  btn.dataset.liked = !isLiked;
  btn.textContent = !isLiked ? '❤️ 已赞' : '? 赞';
}

<div class="task" data-status="pending">待处理任务</div>
<div class="task" data-status="done">已完成任务</div>

.task[data-status="pending"]::before {
  content: "⏳ ";
}
.task[data-status="done"]::before {
  content: "✅ ";
}

<a href="#" data-modal-target="news" data-animation="fade">查看新闻</a>

document.querySelectorAll('[data-modal-target]').forEach(link => {
  link.addEventListener('click', e => {
    e.preventDefault();
    const target = link.dataset.modalTarget;
    const anim = link.dataset.animation;
    openModal(target, anim);
  });
});