chrome/browser/resources/connectors_internals/connectors_tabs.html

<style>
.tabs {
  background-color: #f1f1f1;
  border: 1px solid #ccc;
  overflow: hidden;
}

.tabs button {
  background-color: inherit;
  border: none;
  cursor: pointer;
  float: left;
  outline: none;
  padding: 14px 16px;
  transition: 300ms;
}

.tabs button:hover {
  background-color: #ddd;
}

.tabs button.active {
  background-color: #ccc;
}

.tabcontent {
  border: 1px solid #ccc;
  border-top: none;
  padding: 6px 12px;
}

.hidden {
  display: none;
}
</style>

<!-- Tabs and their contents will be added dynamically. -->
<div class='tabs'>
</div>
<div class='content'>
</div>
<p id='no-connectors-message' class='hidden'>
  There are currently no displayable connectors.
</p>