.required-mark::after {
      content: "必須";
      background-color: #f04e56;
      color: #fff;
      font-size: 12px;
      font-weight: bold;
      min-width: 10px;
      padding: 3px 7px;
      margin: 0px 5px;
      line-height: 1;
      vertical-align: middle;
      white-space: nowrap;
      text-align: center;
      border-radius: 10px;
      display: inline-block;
}