.abs-{position}</code>, <code class="highlighter-rouge">.fix-{position}</code>, <code class="highlighter-rouge">.sti-{position}</code>.
We use the first letter of each position word for short,
all position abbreviations are listed in the below table.</p>

<div class="table table-border">
  <table>
    <thead>
      <tr><th>Abbreviation</th><th>Position</th></tr>
    </thead>
    <tbody>
      <tr><td>t</td><td>top</td></tr>
      <tr><td>r</td><td>right</td></tr>
      <tr><td>b</td><td>bottom</td></tr>
   