Scrollable Lightbox

Absolute positioned Lightbox (% height, fixed width) with absolute positioned header and footer and fixed (%) height scrollable content area.

HTML

<div class="container-1">
    <div class="container-2">
        <div class="container-3"></div>
        <div class="container-5">
            <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
            <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
            <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
            <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
            <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
            <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem...

CSS

* {
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
}

.container-1 {
    position: absolute;
    width: 10%;
    height: 100%;
    background: rgba(0,0,0,.4);
}

.container-2 {
    position: absolute;
    top: 5%;
    left: 50%;
    margin: 0 0 0 -250px;
    width: 500px;
    height: 90%;
    background: green;
    box-shadow: 0 1px 3px rgba(0,0,0,.5);
}

.container-3 {
    position: absolute;
    width: 100%;
    height: 20px;
    top: 0;
    background: yellow;
}

.container-4 {
    position: absolute;
    width: 100%;
    height: 20px;
    bottom: 0;
    background: yellow;
}

.container-5 {
    padding: 30px 60px;
    width: 100%;
    height: 100%;
    background: red;
    opacity: 1;
    overflow-y: auto;
}

p {
    font-size: 16px;
    line-height: 24px;
}