If you have a
<div>, which width is 100%, it can give some problems if you add a padding. The width of the div would then become 100% + padding (ex. 100% + 20px).
But there is a really simple solution to that problem.
Instead of setting the width of the div to 100%, set it to auto, and be sure, that the
<div> is set to
display: block (default for