Given a set of items, add the correct outside "margin"
class-driven approach.
There are two versions, in index.html and indexjs.html, one has a script tag and the other one is only html.
The html-only version does not handle wrapping constrained rows in a wrapper. The jS version generates the content and can generate constrained rows inside a wrapper, aswell as just constrained rows.
Site-wide padding can also be set in the <style>-tag on the body tag and in the media-queries.