純粋な CSS を使用してモーダル ボックスの完璧なレイアウトを実装するためのガイド

<button id="modalBtn">打开模态框</button>

<div class="modalContainer">
  <div class="modalContent">
    <h2>模态框标题</h2>
    <p>这里是模态框的内容。</p>
    <button id="closeBtn">关闭模态框</button>
  </div>
</div>

.modalContainer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 9999;
}

.modalContent {
  width: 400px;
  background-color: #fff;
  padding: 20px;
  border-radius: 5px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  text-align: center;
  transform: translateY(-50%);
  opacity: 0;
  transition: all 0.3s ease-in-out;
}

.modalContainer.active {
  pointer-events: auto;
}

.modalContent.active {
  opacity: 1;
}

.modalContent.active h2 {
  margin-top: 0;
}

.modalContent.active p {
  margin-bottom: 20px;
}

.modalContent.active button {
  display: block;
  margin: 0 auto;
}

const modalBtn = document.getElementById('modalBtn');
const closeBtn = document.getElementById('closeBtn');
const modalContainer = document.querySelector('.modalContainer');

modalBtn.addEventListener('click', toggleModal);
closeBtn.addEventListener('click', toggleModal);

function toggleModal() {
  modalContainer.classList.toggle('active');
}