Pure CSS Treeview Menu

A css only treeview menu without the use of Javascript.

HTML

<div class="css-treeview">
    <ul>
        <li><input type="checkbox" id="item-0" /><label for="item-0">This Folder is Closed By Default</label>
            <ul>
                <li><input type="checkbox" id="item-0-0" /><label for="item-0-0">Ooops! A Nested Folder</label>
                    <ul>
                        <li><input type="checkbox" id="item-0-0-0" /><label for="item-0-0-0">Look Ma - No Hands!</label>
                            <ul>
                                <li><a href="./">First Nested Item</a></li>
                                <li><a href="./">Second Nested Item</a></li>
                                <li><a href="./">Third Nested Item</a></li>
                                <li><a href="./">Fourth Nested Item</a></li>
                            </ul>
                        </li>
                        <li><a href="./">Item 1</a></li>
                        <li><a href="./">Item 2</a></li>
                        <li><a href="./">Item 3</a></li>
                    </ul>
                </li>
                <li><input type="checkbox" id="item-0-1" /><label for="item-0-1">Yet Another One</label>
                    <ul>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                    </ul>
                </li>
                <li><input type="checkbox" id="item-0-2" disabled="disabled" /><label for="item-0-2">Disabled Nested Items</label>
                    <ul>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                    </ul>
                </li>
                <li><a href="./">item</a></li>
                <li><a href="./">item</a></li>
                <li><a href="./">item</a></li>
                <li><a href="./">item</a></li>
        </ul>
</li>
<li><input type="checkbox" id="item-1" checked="checked" /><label for="item-1">This One is Open by Default...</label>
        <ul>
            <li><input type="checkbox" id="item-1-0" /><label for="item-1-0">And Contains More Nested Items...</label>
                <ul>
                    <li><a href="./">Look Ma - No Hands</a></li>
                    <li><a href="./">Another Item</a></li>
                    <li><a href="./">And Yet Another</a></li>
                </ul>
            </li>
            <li><a href="./">Lorem</a></li>
            <li><a href="./">Ipsum</a></li>
            <li><a href="./">Dolor</a></li>
            <li><a href="./">Sit Amet</a></li>
        </ul>
</li>
<li><input type="checkbox" id="item-2" /><label for="item-2">Can You Believe...</label>
        <ul>
                <li><input type="checkbox" id="item-2-0" /><label for="item-2-0">That This Treeview...</label>
                    <ul>
                        <li><input type="checkbox" id="item-2-2-0" /><label for="item-2-2-0">Does Not Use Any JavaScript...</label>
                            <ul>
                                <li><a href="./">But Relies Only</a></li>
                                <li><a href="./">On the Power</a></li>
                                <li><a href="./">Of CSS3</a></li>
                            </ul>
                        </li>
                        <li><a href="./">Item 1</a></li>
                        <li><a href="./">Item 2</a></li>
                        <li><a href="./">Item 3</a></li>
                    </ul>
                </li>
                <li><input type="checkbox" id="item-2-1" /><label for="item-2-1">This is a Folder With...</label>
                    <ul>
                        <li><a href="./">Some Nested Items...</a></li>
                        <li><a href="./">Some Nested Items...</a></li>
                        <li><a href="./">Some Nested Items...</a></li>
                        <li><a href="./">Some Nested Items...</a></li>
                        <li><a href="./">Some Nested Items...</a></li>
                    </ul>
                </li>
                <li><input type="checkbox" id="item-2-2" disabled="disabled" /><label for="item-2-2">Disabled Nested Items</label>
                    <ul>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                        <li><a href="./">item</a></li>
                    </ul>
                </li>
            </ul>
        </li>
    </ul>
</div>

CSS

.css-treeview ul,
.css-treeview li
{
    padding: 0;
    margin: 0;
    list-style: none;
}
 
.css-treeview input
{
    position: absolute;
    opacity: 0;
}
 
.css-treeview
{
    font: normal 11px "Segoe UI", Arial, Sans-serif;
    -moz-user-select: none;
    -webkit-user-select: none;
    user-select: none;
}
 
.css-treeview a
{
    color: #00f;
    text-decoration: none;
}
 
.css-treeview a:hover
{
    text-decoration: underline;
}
 
.css-treeview input + label + ul
{
    margin: 0 0 0 22px;
}
 
.css-treeview input ~ ul
{
    display: none;
}
 
.css-treeview label,
.css-treeview label::before
{
    cursor: pointer;
}
 
.css-treeview input:disabled + label
{
    cursor: default;
    opacity: .6;
}
 
.css-treeview input:checked:not(:disabled) ~ ul
{
    display: block;
}
 
.css-treeview label,
.css-treeview label::before
{
    background: url("../pages/css3-treeview/example/icons.png") no-repeat;
}
 
.css-treeview label,
.css-treeview a,
.css-treeview label::before
{
    display: inline-block;
    height: 16px;
    line-height: 16px;
    vertical-align: middle;
}
 
.css-treeview label
{
    background-position: 18px 0;
}
 
.css-treeview label::before
{
    content: "";
    width: 16px;
    margin: 0 22px 0 0;
    vertical-align: middle;
    background-position: 0 -32px;
}
 
.css-treeview input:checked + label::before
{
    background-position: 0 -16px;
}
 
/* webkit adjacent element selector bugfix */
@media screen and (-webkit-min-device-pixel-ratio:0)
{
    .css-treeview 
    {
        -webkit-animation: webkit-adjacent-element-selector-bugfix infinite 1s;
    }
 
    @-webkit-keyframes webkit-adjacent-element-selector-bugfix 
    {
        from 
        { 
            padding: 0;
        } 
        to 
        { 
            padding: 0;
        }
    }
}

Demo


Source