The solution is to simply not declare width: 100%
.
The default is width: auto
, which for block-level elements (such as div
), will take the “full space” available anyway (different to how width: 100%
does it).
See: http://jsfiddle.net/U7PhY/2/
Just in case it’s not already clear from my answer: just don’t set a width
on the child div
.
You might instead be interested in box-sizing: border-box
.