<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Reference</title>
<style>
  table { border-spacing: 2px; }
  td { border: 1px solid; }
  td, div { width: 10px; height: 10px; }
  div.opc { opacity: 0.99; }
  div.green { background: green; }
  div.up { margin-top: -10px; }
  div.red { background: red; }
</style>
<body>
  <p>Each of the following boxes should have a green or
  very-nearly-green square inside of it:</p>
  <table><tr>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="red"></div>
      <div class="up opc green"></div>
    </td>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="red"></div>
      <div class="up opc green"></div>
    </td>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="red"></div>
      <div class="up opc green"></div>
    </td>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="green"></div>
    </td>
    <td>
      <div class="red"></div>
      <div class="up opc green"></div>
    </td>
    <td>
      <div class="red"></div>
      <div class="up opc green"></div>
    </td>
  </tr></table>
</body>
