Best Answer Danny , 25 August 2014 - 09:11 AM
Yeah I mentioned in my previous post, as far as I am concerned (I could be wrong), the simplest way to have a full width header and have a fixed width content area is to use the full width mode and then apply custom CSS to your content area giving it a background color, padding etc...
I did this quick in Chrome dev tools - https://cloudup.com/cN5FbT6R4rd
You're going to need use additional CSS on the footer too. In regards to that code provided in Batmans post, that code can not work in Boxed mode, I've tried and it doesn't work, but does in Full Width mode. Whether this is to do with updates to DMS or the code is out dated, I don't know. Basically, Box mode wraps everything in a container which has a specific width, margins etc.. it is not possible to achieve a full width element without extensive CSS to my knowledge.
The best thing I can recommend is that you play about in Chrome dev tools, I have provided the basic code I used for as a starting point, but please be aware we do not provide extensive CSS/LESS support which in my opinion this requires.