NoJS Drop Menu

HTML

<label for="dropclose">
 <ul class="menu">
        <li>
            <input type="radio" name="menuopt" id="drop1" />
            <label class="opener" for="drop1">Parent item 1</label>
            <label class="closer" for="dropclose">Parent item 1</label>
            <ul>
                <li><a href="">Menu item 1</a></li>
                <li><a href="">Menu item 2</a></li>
                <li><a href="">Menu item 3</a></li>
            </ul>
        </li>
        <li>
            <input type="radio" name="menuopt" id="drop2" />
            <label class="opener" for="drop2">Parent item 2</label>
            <label class="closer" for="dropclose">Parent item 2</label>
            <ul>
                <li><a href="">Menu item 1</a></li>
                <li><a href="">Menu item 2</a></li>
                <li><a href="">Menu item 3</a></li>
                <li><a href="">Menu item 4</a></li>
                <li><a href="">Menu item 5</a></li>
            </ul>
            <input type="radio" name="menuopt" id="dropclose" />
        </li>
    </ul>
    <div>
      <h1>A bunch of other content</h1>
      <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur blandit aliquam suscipit. Vivamus ac mi tellus. Donec vulputate sem eu justo ornare, at mattis augue tempor. Nullam fringilla odio lobortis bibendum lobortis. Fusce condimentum ultricies nulla, non posuere sem vestibulum nec. Duis rhoncus velit lobortis odio interdum, quis aliquam ex dapibus. Quisque hendrerit pellentesque turpis non pretium. Nam ante metus, tempus quis tortor lacinia, efficitur ullamcorper erat. Sed at aliquet nisi, ac congue massa.</p>
      <p>Mauris est odio, tempor in ex ac, cursus iaculis ex. Etiam eu dapibus dolor. Quisque sodales mollis neque fringilla maximus. Praesent malesuada vitae elit eu congue. Mauris fringilla maximus arcu sit amet tempor. Nam sagittis lectus massa, eu viverra enim congue a. Nunc ultrices sapien nec enim auctor, ac placerat velit posuere. Donec velit...

CSS

.menu ul, 
    .menu input, 
    .menu .closer, 
    .menu input:checked ~ .opener{
        display:none;
    }
    .menu input:checked ~ ul,
    .menu input:checked ~ .closer{
        display:block;
    }