I’m trying to put the divs div.mes and div.vazio on same line. If I remove the margin from two divs (QuadroPrincipal and ul_mes) I get the result I want.
The problem is that I need divs mes and vazio on same line keeping the margins on elements quadroPrincipal and ul_mes.
Take a look: http://jsfiddle.net/4Zjx8/5/
I want to build this example:

How about not making
.mes‘s width 100%? Also, you need to specify what behaviour you need; should.vaziobe displayed partially? Should.mesgive way and become less wide? Do you actually need percentages? Is the container a fixed width so the widths in the example/fiddle would always be some known value? (e.g. if container width = 1000 and.foowould be 75% it would always be 750px (exluding margins etc.)).