options.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>PolyGerrit Options</title>
<style>
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  label,
  button {
    cursor: pointer;
  }
  input[type="checkbox"] {
    margin-right: 4px;
    vertical-align: -2px;
  }
  .bottomContainer {
    align-items: center;
    display: flex;
    margin-top: 10px;
  }
  .saveButton {
    margin-right: 10px;
  }
  .statusMessage {
    color: #666;
  }
</style>
<body>
<label>
  <input type="checkbox" class="likeCheckbox">
  Always use canary on *.googlesource.com domains
</label>
<div class="bottomContainer">
  <button class="saveButton">Save</button>
  <div class="statusMessage"></div>
</div>
<script src="options.js"></script>