:indeterminate伪类与单选框组的选择提示实例页面

展示

代码

• HTML：

  <input type="radio" id="radio1" name="radio">
  <label for="radio1" class="cs-radio"></label>
  <label for="radio1">单选项1</label>
  <input type="radio" id="radio2" name="radio">
  <label for="radio2" class="cs-radio"></label>
  <label for="radio2">单选项2</label>
  <input type="radio" id="radio3" name="radio">
  <label for="radio3" class="cs-radio"></label>
  <label for="radio3">单选项3</label>
  <-- 这里显示提示信息 -->
  <p class="cs-valid-tips"></p>

• CSS：

  [type="radio"] {
      position: absolute;
      width: 20px; height: 20px;
      opacity: 0;
      cursor: pointer;
  }
  /* 单选框 */
  .cs-radio {
    display: inline-block;
    width: 20px; height: 20px;
    border: 1px solid gray;
    border-radius: 50%;
    background-color: #fff;
    box-sizing: border-box;
    vertical-align: -.5ex;
    user-select: none;
    transition: border-color .2s;
    overflow: hidden; 
  }
  :checked + .cs-radio {
    border-color: deepskyblue; 
  }
  :checked + .cs-radio::before {
    content: "";
    display: block;
    width: 10px; height: 10px;
    margin: 4px auto 0;
    border-radius: 50%;
    background-color: deepskyblue;
  }
  
  :indeterminate ~ .cs-valid-tips::before {
      content: "您尚未选择任何选项";
      color: red;
      font-size: 87.5%;
  }