Scrolling horizontally causes UI elements to clash with TreeView in aside

[sirocyl]

Seen on the docs page - don't know if it's specific to that or more of a global concern.

Observed behavior:

When the page is wide enough to scroll horizontally - for instance, opening the "Show Code" on the Tabs view - some XP UI elements draw over the TreeView located in the aside.

Expected behavior:

Either:

• Easiest: UI elements should draw underneath the TreeView in a fixed-position aside (aside z-indexes above the rest)
• Most proper: Aside should be free to scroll left and right, but remain fixed vertically.

This is also observed upstream, in 98.css - for example. A report has been made there as well.

Example below:

[botoxparty]

Yep this is just a docs thing, I need to work out how i'm going to structure the docs to accommodate for other themes and will fix this then.

Thanks for reporting.