chore(ui): add light mode to code elements

[avivkeller]

Fixes nodejs/doc-kit#940 by using github-light when light mode is selected

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
nodejs-org	Ready	Preview	Jul 28, 2026 10:50pm

[cursor]

PR Summary

Low Risk
Presentation-only theming for syntax highlighting and code UI; custom Shiki theme overrides in consumers are still respected.

Overview
Adds light-mode support for docs code blocks by switching Shiki from a single Nord theme to paired github-light (default) and Nord-based dark themes, with CSS that applies --shiki-dark* token overrides when [data-theme='dark'].

Code chrome (BaseCodeBox, CodeTabs, and neutral BaseButton) now uses light surfaces and text by default, with existing dark: variants preserved. Twoslash hover popups get matching light backgrounds and a dark-theme override.

A patch changeset and a highlighter unit test assert dual-theme output (light/dark, defaultColor: 'light').

^{Reviewed by Cursor Bugbot for commit 31efd11. Bugbot is set up for automated code reviews on this repo. Configure here.}

[codecov]

Codecov Report

❌ Patch coverage is 90.47619% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.15%. Comparing base (c086c54) to head (31efd11).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
packages/rehype-shiki/src/highlighter.mjs	90.47%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9031      +/-   ##
==========================================
+ Coverage   75.10%   75.15%   +0.05%     
==========================================
  Files         102      102              
  Lines        9109     9124      +15     
  Branches      372      374       +2     
==========================================
+ Hits         6841     6857      +16     
+ Misses       2264     2263       -1     
  Partials        4        4              

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[github-actions]

📦 Build Size Comparison

Summary

Metric	Value
Old Total First Load JS	10.65 MB
New Total First Load JS	10.70 MB
Delta	44.11 KB (+0.40%)

Changes

🔄 Modified Routes (4)

Route	Old First Load JS	New First Load JS	Delta
/[locale]	2.54 MB	2.55 MB	📈 11.03 KB (+0.42%)
/[locale]/[...path]	2.54 MB	2.55 MB	📈 11.03 KB (+0.42%)
/[locale]/blog/[...path]	2.54 MB	2.55 MB	📈 11.03 KB (+0.42%)
/[locale]/download/archive/[version]	2.54 MB	2.55 MB	📈 11.03 KB (+0.42%)