Remove the wrapper specifies the width (it's a block element, and so he takes all the available width) and add a negative margin left and right margin equal elements. Vzhuh. It is a normal practice.
The alternative is to use grids or to practice your method, but it is not necessary to write hands, there are
specialized tools for this.
Styles get excessive (although, in General, is not much more than hands to write), but it works and reinforced concrete in terms of a DX great.