The webpage layout is Div + CSS, which can be centered in IE and cannot be centered in Firefox. How can this problem be solved on the left?

Webpage layout Div + CSS, which can be centered in IE, cannot be centered on Firefox, left

 

Style = "margin-left: auto; margin-Right: auto; width: 640px ;"

 

During the first test with Firefox, you may find that
The frame normally displayed in the center of IE cannot be displayed in the center and cannot be adjusted. This is a headache... Me too ,-
-! We usually use the following Center Method in IE:Text-aglin: center;
It is ineffective in Firefox. The method of centering in Firefox is as follows:
Yes:Style {margin: 0 auto}

=> Style {margin: 0 auto}. We regard auto as "Auto" or "whatever", but I think it is more appropriate to think "auto extension, that is to say, when you set one side or multiple sides, the rest will automatically extend. In this way, you can imagine why the location in Firefox is determined...

For example:

Center margin: 0 auto
Left margin: 0 auto 0 0
Right margin: 0 0 0 auto