The absolute positioning method of Div center is compatible with IE series browsers and Firefox browsers.

For more information, see the style:
# Dingwei {padding: 10px; Background-color: #003300; color: # ffffff;
Width: 600px; Height: 300px;
Display: block;
Position: absolute;
Top: 50%;
Left: 50%;
Margin-left:-300px;
Margin-top:-150px ;}

Padding: 10px; Background-color: #003300; color: # ffffff;

Width: 600px; Height: 300px; the total width and height of the DIV are set according to your actual situation;

Display: block; display the DIV as a block-level element;

Position: absolute; top: 50%; left: 50%; margin-left:-300px; margin-top:-150px, I think all smart friends can see it.
It is definitely positioning the DIV layer. Of course, you should make it relative to the body tag. Margin-left:-Px; this value is half the DIV width, and margin-top:-150px; is half the DIV height.