background-color: #f4f4f4;
      }

      expand-button {
        -webkit-user-select: none;
        cursor: pointer;
        margin-right: 3px;
        font-size: smaller;
        height: 1rem;
      }

      expand-button.button-expanded {
        transform: rotate(90deg);
      }
    </style>
    <table>
      <colgroup id="cols">
      </colgroup>
      <thead id="head">