Hi Customer (name blocked for privacy). Thank you for asking your question on Just Answer.
Actually, this isn't really a newbie mistake - it has to do with the different rendering engines in use by different browsers. Unfortunately, there is no easy fix for this type of problem. It doesn't help at all that most browsers don't fully support the CSS specifications anyway. As far as I know, you'll never get the exact same result in all different browsers, but you can get close by using various tricks to get the job done.
The first thing I can think of on the spot is trying a switch to the em unit of measurement in your styles. If I recall correctly, the em unit is less "dynamic" across browsers. The downfall is that em is based on the size of the font in use on the page (or in the element, such as the div), so to get a consistent result you'll probably have to specifically that size as well.
There are a couple of resources that might point you in the right direction. First, the built-in CSS reference in Dreamweaver is pretty good for general information. Second,
this page might help get you on the right page for cross-browser support.
Keep in mind that it is
VERY hard to get some sites to look the same in all major browsers using CSS. I have spent many an afternoon trying to figure out why one of my pages loads fine in Firefox, but looks totally different in IE. My own golden rule is that if the page is relatively simple, use a table layout if possible. Many people will disagree with me, but given that CSS isn't that well executed in many browsers, it is sometimes necessary to go back to tables.
Finally, if you can upload your page somewhere, I can take a look and tinker with it a bit myself and perhaps provide some further help.
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