Feature summary (what you would like to be able to do and where):
In Vector 2022, the main sidebar is currently significantly wider than previous sidebars, on some wikis leaving a lot of unused horizontal space and resulting in a main sidebar much wider than the tools sidebar on the opposite side.
FR: Make this a site-wide setting, so that sites that don't make use of the main sidebar width can leave it compact.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
On Commons for instance, most visitors are viewing the page for a file, which currently has two primary features:
- no TOC, so the left-hand sidebar is half unused
- a prominent right-aligned template showing other related images (which pushes down the body text on narrow screens, as the body text starts with a full-width thumbnail of the file, so extra width is at a premium.
Commons editors+designers might want to default to a wide central column and narrow sidebars.
Two images showing the effect with narrow-width, and the extra h-padding in the left margin even at wide-width
Benefits (why should this be implemented?):
Community-centered design, flexibility, minimal wasted energy around skin updates.