Make Div overlay ENTIRE page (not just viewport)?

So I have a problem that I think is quite common but I have yet to find a good solution for. I want to make an overlay div cover the ENTIRE page... NOT just the viewport. I don't understand why this is so hard to do... I've tried setting body, html heights to 100% etc but that isn't working. Here is what I have so far:

<html>
<head>
    <style type="text/css">
    .OverLay { position: absolute; z-index: 3; opacity: 0.5; filter: alpha(opacity = 50); top: 0; bottom: 0; left: 0; right: 0; width: 100%; height: 100%; background-color: Black; color: White;}
    body { height: 100%; }
    html { height: 100%; }
    </style>
</head>

<body>
    <div style="height: 100%; width: 100%; position: relative;">
        <div style="height: 100px; width: 300px; background-color: Red;">
        </div>
        <div style="height: 230px; width: 9000px; background-color: Green;">
        </div>
        <div style="height: 900px; width: 200px; background-color: Blue;"></div>
        <div class="OverLay">TestTest!</div>
    </div>


    </body>
</html>

I'd also be open to a solution in JavaScript if one exists, but I'd much rather just be using some simple CSS.

The viewport is all that matters, but you likely want the entire website to stay darkened even while scrolling. For this, you want to use position:fixed instead of position:absolute. Fixed will keep the element static on the screen as you scroll, giving the impression that the entire body is darkened.

Example: http://jsbin.com/okabo3/edit

div.fadeMe {
  opacity:    0.5; 
  background: #000; 
  width:      100%;
  height:     100%; 
  z-index:    10;
  top:        0; 
  left:       0; 
  position:   fixed; 
}

<body>
  <div class="fadeMe"></div>
  <p>A bunch of content here...</p>
</body>

body:before {
    content: " ";
    width: 100%;
    height: 100%;
    position: fixed;
    z-index: -1;
    top: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.5);
}

First of all, I think you've misunderstood what the viewport is. The viewport is the area a browser uses to render web pages, and you cannot in any way build your web sites to override this area in any way.

Secondly, it seems that the reason that your overlay-div won't cover the entire viewport is because you have to remove all margins on BODY and HTML.

Try adding this at the top of your stylesheet - it resets all margins and paddings on all elements. Makes further development easier:

* { margin: 0; padding: 0; }

Edit: I just understood your question better. Position: fixed; will probably work out for you, as Jonathan Sampson have written.

Make Div overlay ENTIRE page (not just viewport)?

Related

Recent Posts