Breaking this out as a specific issue related to T327719 , for clarity.

The initial release had two issues with sidebar style that were frequently mentioned:

• The sidebar had too much horizontal spacing, and no non-whitespace delineation from the body text.
• The sidebar-TOC wrapped TOC lines, added a line for counting comments, and was free with vertical linespace, making it hard to see more than 12-15 sections at once, or even see how many there were overall, requiring an in-sidebar TOC-scrollbar. This is particularly rough for pages frequented by active editors that regularly have 100+ sections: popular talk pages, noticeboards, user-talk pages of very active users.

The late-Jan update magnified both of these issues, trending away from the style of navigation and tool templates within articles (i.e.: compact, carefully-kerned, visibly different from the rest of the page, for recurring sections that are repeated across many pages in predictable places on the page). Some specific changes away from that style:

• Sidebar text is now the same font size as body text. This is hard to scan + differentiate.
• Sidebar linespacing is now larger than that of the body text. This is hard to read and a significant stylistic change.
• Sidebar sections are harder to scan: no font-face or font-size difference between section titles and links in the section, and no distinguishing linespacing.

These choices differ from the style of most infoboxes and navboxes on WM wikis. I would be keen to see examples of this that work well on other sites, online or in print. Tools + Main Menu sidebars are also asymmetric (more discussion in T324877)

• Different spacing b/t them and the body
• Different horizontal placement w/in their side
• Different vertical alignment w/ the page
• Different line alignment of the bottom of each line (they don't line up)
• Different behavior when clicking "hide", different icon/text/caret for unhiding
• Interlanguage links now appear in all possible places, adding to the confusion. (language selector up top, 'Translations' in the user menu dropdown, prominent box saying 'your languages are in another castle' on the L, "edit interlanguage links" link — now the only instance of smaller font! — on the R)

I am stymied by all this :) Newcomers and readers may be too, with less recourse.

Screenshots of the misalignment across the sidebars (observed on chrome + ff / macos):

Expected behavior:

I expected a bit more alignment in approach and style between sidebar nav and main-content nav, so we're all iterating towards the same goals.

1. A sidebar style that matches the style of navigation in project content.
2. A process for rolling out changes as significant as sidebar functionality + readability to a subset of users for feedback, including a subset of community-layout-maintainers, not to all Vector 2022 users and all anons
3. Maintaining roughly the padding and font-size and linespacing of the V2010 sidebar, with distinguishable sidebar headings. This is not particularly low-hanging fruit to improve -- unlike the idea of making use of the right hand margin -- and there's a downside to experimentally changing this for everyone.
4. Continuing to support magic words like TOC. This gives editors recourse to improve the reading experience for pages rendered less usable by the change: those with long TOCs, or those that rely on readers being able to see the whole TOC at once or to see numbered sections.