html - box-shadow on top of children

Question

How do I get an inset CSS3 box-shadow to render on top of its children elements?

Problem:

HTML:

<div id="chatroom">
    <div class="chatmessage"><b>User 1:</b>Test</div>
    <div class="chatmessage"><b>User 2:</b>Test</div>
    <div class="chatmessage"><b>User 1:</b>Test</div>
    <div class="chatmessage"><b>User 2:</b>Test</div>
</div>

CSS:

#chatroom{
    border: 1px solid #CCC;
    height: 135px;
    font-size: 0.75em;
    line-height: 1.2em;
    overflow: auto;
    -moz-box-shadow: inset 0 0px 4px rgba(0,0,0,.55);
    -webkit-box-shadow: inset 0 0px 4px rgba(0,0,0,.55);
}
.chatmessage{
    padding: 4px 2px;
}
.chatmessage b{
    margin-right: 2px;
}
.chatmessage:nth-child(2n) {
    background: #EEE;
}

question from:https://stackoverflow.com/questions/2402473/box-shadow-on-top-of-children

Answer 1

To avoid the use of an additional element, you can use css pseudo-elements. Try this demo.

#chatroom {
    position: relative;
}

#chatroom:before {
    content: "";

    /* Expand element */
    position: absolute;
    left: 0px;
    top: 0px;
    right: 0px;
    bottom: 0px;

    -moz-box-shadow: inset 0 0 8px rgba(0,0,0,.55);
    -webkit-box-shadow: inset 0 0 8px rgba(0,0,0,.55);
    box-shadow: inset 0 0 8px rgba(0,0,0,.55);

    /* Disable click events */
    pointer-events: none;
}

Basically this css creates that additional element for you. Notice the pointer-events:none to allow click events to pass through this element.

Keep in mind that pointer-events:none doesn't work well on some mobile devices regarding touch scrolling (clicking/taping works well). I ended up not using inset shadows at all because of this.