Question

I’m trying to create overlay for modal window.
Here is my css

#overlay {
 position: absolute;
 background: #000;
 width: 100%;
 height: 100%;
 z-index: 9800;
}

The problem is that layer does not cover entire page. When I scroll down overlay disappear.
What I miss ?

Answer 1

Use fixed positioning:

position: fixed;

You should have:

#overlay {
 position: fixed;
 background: #000;
 width: 100%;
 height: 100%;
 z-index: 9800;
}