weseek__growi/lib/views/widget/system-version.html

<div class="system-version hidden-xs">
  <span>
    <a href="https://growi.org">GROWI</a> {{ growiVersion() }}
  </span>
  <span>
    <a href="" data-target="#shortcuts-modal" data-toggle="modal"><i class="fa fa-keyboard-o"></i>&nbsp;<span class="cmd-key"></span>-/</a>
  </span>
</div>
<script>
  /*
  * add classes to cmd-key by OS
  */
  var platform = navigator.platform.toLowerCase();
  var isMac = (platform.indexOf('mac') > -1);

  document.querySelectorAll('.system-version .cmd-key').forEach((element) => {
    if (isMac) {
      element.classList.add('mac');
    }
    else {
      element.classList.add('win');
    }
  });
</script>