Re: CSS / HTML Help
100% is the width of the content. Onto that, you have added a border and some padding, so the actual width of the box is 100% plus 4px for the borders plus 15px for the left-side padding. Just leave the 100% out of the deal, and any standards-compliant browser will do what it's supposed to do -- assume that the block-level element spans its entire container. It's only when you specify a width that it should act differently.
“Beware of bugs in the above code; I have only proved it correct, not tried it.” --Donald Knuth
"It was as if its architects were given a perfectly good hammer and gleefully replied, 'neat! With this hammer, we can build a tool that can pound in nails.'" -- Alex Papadimoulis (on TheDailyWTF.com)