"wrapper">
  <div class="grid" data-expected-width="300" data-expected-height="200">
    <div class="item" data-offset-x="200" data-offset-y="150" data-expected-width="100" data-expected-height="50"></div>
  </div>
</div>

<div class="wrapper">
  <div class="grid" style="width: 200px; height: 100px;" data-expected-width="200" data-expected-height="100">
    <div class="item" data-offset-x="100" data-offset-y="50" data-expected-width="100" data-expected-height="50"></div>
  </div>
</div>

<div class="wrapper