修改 input checkbox(复选框) 选中的背景颜色

 input[type=checkbox] {
    width: 15px;
    height: 15px;
    margin-right: 10px;
    position: relative;
  }
  input[type=checkbox]::after {
    position: absolute;
    top: 0;
    color: #000;
    width: 15px;
    height: 15px;
    display: inline-block;
    visibility: visible;
    padding-left: 0;
    text-align: center;
    content: ' ';
    // border-radius: .03rem;
  }
  input[type=checkbox]:checked::after {
    content: "✓";
    color: #fff;
    font-size: 10px;
    line-height: 15px;
    background-color: red;
    
  }