<div class="container">
  <ul>
    <li class="list-item">Unordered list item</li>
  </ul>
  <ol>
    <li class="list-item">Ordered list item</li>
  </ol>

  <div class="list">
    <div class="list-item">display list item</div>
  </div>
</div>

<div class="form">
  <label for="content">content(for ::before):</label>
  <select name="content" id="contet">
    <option value="'»'">»</option>
    <optgroup label="字符">
      <option value="'Go!'">Go!</option>
    </optgroup>
    <optgroup label="HTML实体符">
      <option value="'➤'">➤</option>
      <option value="'❢'">'❢'</option>
      <option value="'\2762'">'\2762'</option>
    </optgroup>
    <optgroup label="表情符号">
      <option value="'🔥'">🔥</option>
      <option value="'🐻'">'🐻'</option>
      <option value="'\01F33A'">'\01F33A'</option>
    </optgroup>
    <optgroup label="图片">
      <option value="url('//www.w3cplus.com/sites/default/files/blogs/2021/2108/rocket.svg')">url(//www.w3cplus.com/sites/default/files/blogs/2021/2108/rocket.svg)</option>
    </optgroup>
  </select>
</div>

@import url("https://fonts.googleapis.com/css2?family=Exo:wght@600&display=swap");

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  inline-size: 100vw;
  min-block-size: 100vh;

  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: "Exo", Arial, sans-serif;
  background-color: #f7f7f7;
  line-height: 2;
}

.container {
  padding: 40px;
  background: #fff;
  box-sizing: border-box;
  box-shadow: 0 2px 4px rgb(0 0 0 / 20%);
  min-width: 60vw;
  max-width: 60vw;
  border-radius: 5px;
  position: relative;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 200px), 1fr));
  gap: 20px;
  margin-bottom: 20px;
}

select {
  max-width: 200px;
}

:root {
  --content: "»";
}

.list > .list-item {
  display: list-item;
}

.list-item::marker {
  content: none;
}

.list-item::before {
  content: var(--content);
  margin-right: 10px;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  width: 36px;
  height: 36px;
  background-image: conic-gradient(from 30deg, #ff005e, #cc196c, #ff003b);
  background-size: cover;
  border: 1px solid rgba(255, 255, 255, 0.125);
  backdrop-filter: blur(16px) saturate(180%);
  background-color: rgba(17, 25, 40, 0.75);
  border-radius: 50%;
  font-size: 1.325rem;
  text-shadow: 1px 1px 1px #3500ff;
  filter: drop-shadow(1px 1px 2px rgb(0 0 0 / 0.25));
  animation: spin 2.5s ease-in-out infinite;
}

@keyframes spin {
  0% {
    transform: rotate(0deg) scale(1);
  }
  50% {
    transform: rotate(720deg) scale(0.6);
    filter: blur(3px);
  }
  100% {
    transform: rotate(0deg) scale(1);
  }
}

const rootEle = document.documentElement;
const select = document.getElementById("contet");

select.addEventListener("change", (etv) => {
  rootEle.style.setProperty("--content", etv.target.value);
});