<!DOCTYPE html>
    <title>Creating a modal window with HTML5 &amp; CSS3</title>
<!-- source: -->
    .modalDialog {
        position: fixed;
        font-family: Arial, Helvetica, sans-serif;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        background: rgba(0,0,0,0.8);
        z-index: 99999;
        -webkit-transition: opacity 400ms ease-in;
        -moz-transition: opacity 400ms ease-in;
        transition: opacity 400ms ease-in;
        pointer-events: none;

    .modalDialog:target {
        pointer-events: auto;

    .modalDialog > div {
        width: 400px;
        position: relative;
        margin: 10% auto;
        padding: 5px 20px 13px 20px;
        border-radius: 10px;
        background: #fff;
        background: -moz-linear-gradient(#fff, #999);
        background: -webkit-linear-gradient(#fff, #999);
        background: -o-linear-gradient(#fff, #999);

    .close {
        background: #606061;
        color: #FFFFFF;
        line-height: 25px;
        position: absolute;
        right: -12px;
        text-align: center;
        top: -10px;
        width: 24px;
        text-decoration: none;
        font-weight: bold;
        -webkit-border-radius: 12px;
        -moz-border-radius: 12px;
        border-radius: 12px;
        -moz-box-shadow: 1px 1px 3px #000;
        -webkit-box-shadow: 1px 1px 3px #000;
        box-shadow: 1px 1px 3px #000;

    .close:hover { background: #00d9ff; }


<a href="#openModal">Open Modal</a>

<div id="openModal" class="modalDialog">
        <a href="#close" title="Close" class="close">X</a>
        <h2>Modal Box</h2>
        <p>This is a sample modal box that can be created using the powers of CSS3.</p>
        <p>You could do a lot of things here like have a pop-up ad that shows when your website loads, or create a login/register form for users.</p>