Why does it need left property to be centered?

I just go to this site: http://www.domdesignonline.de/.

Take a look at div#siteend, I don't understand why to be centered, i开发者_如何学运维t needs the left property. I'm CSS beginner.

Thanks first.

div#siteend has a width of 100% and it is contained in a div that is less than 100% wide.

This means that if it doesn't have left:0; then the left side of the bounding box will be on the inner-leftside of the parent item (div#wrap).

You could also leave out the left:0; and make the width of div#siteend the same as div#wrap and you would achieve the same effect.

its fixed div to the end of the page .
the fixed div still visible at a definite point whatever you scroll the page they did it with left:0;bottom:0; and its text is cetered with text-align:center;