Filter Form

<div style="max-width: 400px">
  <form class="filter-form">
      <ul>
        <li class="category">
          <fieldset>
            <legend class="category-title">Skill Level</legend>
            <ul>
              <li class="category-option">
                <input id="beginner" type="checkbox">
                <label for="beginner">Beginner</label>
              </li>
              <li class="category-option">
                <input id="intermediate" type="checkbox">
                <label for="intermediate">Intermediate</label>
              </li>
              <li class="category-option">
                <input id="advanced" type="checkbox">
                <label for="advanced">Advanced</label>
              </li>
          </ul>
          </fieldset>
        </li>
        <li class="category">
          <fieldset>
            <legend class="category-title">Type</legend>
            <ul>
              <li class="category-option">
                <input id="bug" type="checkbox">
                <label for="bug">Bug</label>
              </li>
              <li class="category-option">
                <input id="enhancement" type="checkbox">
                <label for="enhancement">Enhancement</label>
              </li>
            </ul>
          </fieldset>
        </li>
      </ul>
  </form>
</div>