How to center a page in a Web page made by Div+css

I write the page is wrapped in a div called #container, so here is mainly about the relationship between body and #container.

First look at the body's CSS style:

body{Margin:0;padding:0;text-align:center;}

Here the body put margin and padding set to 0, so that the body content with the edge of the browser close contact. Then text-align:center the contents of the body all centered, so that includes the #container also centered together.

Let's look at the style of #container:

Container{width:760px;margin:0 auto;text-align:left;position:relative;}

Learning is in this #container: Set the width of the container, here is the 760px,margin:0 auto; Here the first 0 of the margin is up and down, and the second auto is around. Up and down for about 0 let its self-control. Plus positioning as relative, only the relative elements can be positioned to move!