Maybe.

The line-height value, for example, could also affect the vertical positioning. Unless this is zero, the difference in browser font-sizes will cause a difference in line-height, which will have much the same effect as adding different padding to the top and bottom. Try specifying a font-size, or specifying line-height: 0;, or both.

You might also have a conflict of styles, although it's unlikely. You can check this by adding !important after your zero-margin and padding declarations:

Code: Select all

{
margin: 0 !important;
padding: 0 !important;
}

These will override all conflicting rules, provided you have not used !important anywhere else. It's a marvellous CSS debugging tool for when you have complex stylesheets, or a cascade over multiple stylesheets. Be sure to remove it after testing.