Usable changes for demo site

Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

• .container-fluid instead .container
• .highlight pre {white-space: pre-wrap;} instead .highlight pre {white-space: pre;}
• pop-up link/button to toggle to sandbox (CodePen oEmbed or something like this)

Motivation and context

• no horizontal scrolling
• less vertical scrolling
• more readable and interactive

Before: After:

[GeoSot]

To be honest, I liked the idea, and probably could be achieved keeping a cookie/local storage config, but lets wait some more opinions

[rilrom]

There’s accessibility reasons behind having a max-width on main content.

Please refer to https://www.w3.org/WAI/tutorials/page-structure/styling/#line-length for more information.