v4 site polish

[benmccann]

Describe the bug

• update renderer (feat(site): site-kit renderer #8757)
• ensure text in buttons on homepage hero is vertically centered
• can't switch tabs on https://svelte.dev/repl/bf0a554a82a7431caec86b1e234caa52?version=4.0.0
• site: sync to current svelte.dev kit#10187 (comment)
• REPL breaks when deleting attributes sites#496
• check that migration guide code blocks render well for everyone after renderer is updated
• do something scroll bar on windows/linux on accessibility warnings page. e.g. hide as vite does
• remove glow on aside/highlight blocks
• test that deep links scroll properly after renderer is updated
• search needs to scroll to selected item. it's currently going to top of page
• remove text blurring when search overlay is up. just match kit.svelte.dev's current behavior
• double link highlighting. go to https://svelte.dev/blog and hover blog in the header
• copyright notice on homepage should probably span the full width on mobile
• Contrast issues on Examples page sites#493
• Docs : White text on white BG in examples #8816
• Failure loading mapbox on svelte.dev examples  sites#492
• console output in dark mode on https://svelte.dev/repl/148aad2fd19941e091128aaba4170b6e?version=4.0.0
• when on docs, should menu open up to docs sub-menu? it's semi-convenient, but felt confusing at first that menu is different on homepage and docs page

Potential new functionality

• mobile "on this page" - should be collapsed by default if included
• REPL code doesn't load until switching to output tab. could load it sooner

Reproduction

locally or vercel preview

Logs

No response

System Info

`master`

Severity

annoyance

[Loldator]

sveltejs/site-kit#158

sveltejs/site-kit#159

[tanhauhau]

console output dark mode fixed in sveltejs/sites#517

[tanhauhau]

what do you mean by the 3rd item: can't switch tabs on ... ?

looks okay to me right now

[zqianem]

gentle ping for sveltejs/site-kit#164

[etainad008]

Hey, I am looking into "ensure text in buttons on homepage hero is vertically centered".
This problems derives from the Overpass font itself. The characters are not vertically aligned inside the font's box.
The easy fix is, of course, use padding: 0.45em 0.8em 0.25em; on the .cta class. But this breaks easily for obvious reasons.
A more sustainable fix is described here. I will try and implement it and will update on my findings.