:required和:optional伪类标记问卷可选项实例页面

展示

代码

• HTML：

  <form>
      <fieldset>
          <legend>问卷调查</legend>
          <ol class="cs-ques-ul">
              <li class="cs-ques-li">
                  <input type="radio" name="ques1" required>1~3年
                  <input type="radio" name="ques1">3~5年
                  <input type="radio" name="ques1">5年以上
                  <h4 class="cs-caption">你从事前端几年了？</h4>
              </li>
              <li class="cs-ques-li">
                  <input type="radio" name="ques2" required>1~3小时
                  <input type="radio" name="ques2">3~5小时
                  <input type="radio" name="ques2">小时以上
                  <h4 class="cs-caption">你每周多少业余时间用来学习前端技术？</h4>
              </li>
              <li class="cs-ques-li">
                  <input type="radio" name="ques3" required>1~3本
                  <input type="radio" name="ques3">3~5本
                  <input type="radio" name="ques3">5本以上
                  <h4 class="cs-caption">你每年买多少本与前端相关的图书？</h4>
              </li>
              <li class="cs-ques-li">
                  <textarea></textarea>
                  <h4 class="cs-caption">有什么其它想说的？</h4>
              </li>
          </ol>
          <p><input type="submit" value="提交"></p>
      </fieldset>
  </form>

• CSS：

  .cs-ques-ul {
      counter-reset: quesIndex;
  }
  .cs-ques-li {
      display: table;
      width: 100%;
      position: relative;
  }
  /* 前面序号计数显示与定位 */
  .cs-ques-li::before {
      counter-increment: quesIndex;
      content: counter(quesIndex) ".";
      position: absolute; top: .75em;
      margin: 0 0 0 -20px;
  }
  .cs-caption {
      display: table-caption;
      caption-side: top;
  }
  /* 标记必选还是可选 */
  :optional ~ .cs-caption::after {
      content: "（可选）";
      color: gray;
  }
  :required ~ .cs-caption::after {
      content: "（必选）";
      color: red;
  }