Replaces #4965. Rolls back #4895. Fixes#4964. Partially fixes#4819.
The previous attempts to add a stylised "focus" ring, while with the best intentions, did not take into account how "outline" normally works for people using visual aids. Most high contrast software will effect the outline if its available (ie. make it bolder or more prevalant), thus the "outline" property is paramount to maintaining accessibility.
The previous changes also present issues with elements using box-shadows already, and again, on high contrast, box-shadows are no longer rendered.
This change will bring back the outline property for focus, but with an addition to allow a blue highlight for Firefox, would should keep it in "parity" with WebKit.
Refs:
- https://a11yproject.com/posts/never-remove-css-outlines/
- http://www.outlinenone.com
- https://stackoverflow.com/questions/52589391/css-box-shadow-vs-outline
This should make Windows PCs look a little nicer, albeit inconsistent with others (Sergoe UI is unique). If it's good enough for GitHub, then it's good enough for October.
All text shadows have been stripped, along with some box shading. They were barely noticeable and should speed up the UI.
Various sizing fixes
Set the standard padding to 20px
Mute system links unless hover or active
Fixes an issue where the scroll indicator appears always on fancy layout, these containers cannot use padding!
Refs #1895
Ben Thomson
Samuel Georges
Luke Towers
matthew188
Pásztor Gábor
alekseybobkov