I set a default website width to 700 px and when I try to set a sidebar my main content becomes very narrow.
How to make a subpage which contains a custom sidebar to have 700 px + 100 px (or another value) for sidebar instead of 575 px – main content and 175 sidebar for pages which contain sidebar and default value of 700 px for pages without sidebar?
In another words:
700px (main area) + 100px for subpages which contain sidebar
700 px for subpages without sidebar