fix(markdown): update monospace font-face for preformatted code blocks on Windows

[bmuenzenmeyer]

Description

At @avivkeller's suggestion nodejs/doc-kit#910 could be fixed upstream in ui-components, so as to improve all usages

Validation

Setup: add this to any markdown on the site

### 909 Debug Test

```text
┌────────────────────────────────────────────────────────────────────────────────────────────────┐
│                                              href                                              │
├──────────┬──┬─────────────────────┬────────────────────────┬───────────────────────────┬───────┤
│ protocol │  │        auth         │          host          │           path            │ hash  │
│          │  │                     ├─────────────────┬──────┼──────────┬────────────────┤       │
│          │  │                     │    hostname     │ port │ pathname │     search     │       │
│          │  │                     │                 │      │          ├─┬──────────────┤       │
│          │  │                     │                 │      │          │ │    query     │       │
"  https:   //    user   :   pass   @ sub.example.com : 8080   /p/a/t/h  ?  query=string   #hash "
│          │  │          │          │    hostname     │ port │          │                │       │
│          │  │          │          ├─────────────────┴──────┤          │                │       │
│ protocol │  │ username │ password │          host          │          │                │       │
├──────────┴──┼──────────┴──────────┼────────────────────────┤          │                │       │
│   origin    │                     │         origin         │ pathname │     search     │ hash  │
├─────────────┴─────────────────────┴────────────────────────┴──────────┴────────────────┴───────┤
│                                              href                                              │
└────────────────────────────────────────────────────────────────────────────────────────────────┘
(All spaces in the "" line should be ignored. They are purely for formatting.)

Before

After

Related Issues

Closes nodejs/doc-kit#909
Closes nodejs/doc-kit#910

Check List

• I have read the Contributing Guidelines and made commit messages that follow the guideline.
• I have run pnpm format to ensure the code follows the style guide.
• I have run pnpm test to check if all tests are passing.
• I have run pnpm build to check if the website builds without errors.
• I've covered new added functionality with unit tests if necessary.

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Project	Deployment	Actions	Updated (UTC)
nodejs-org	Ready	Preview	Jul 18, 2026 11:36pm

[cursor]

PR Summary

Low Risk
Markdown-only CSS scoped to pre; no auth, data, or API changes—visual typography fix with a patch version bump.

Overview
Fixes misaligned ASCII/box-drawing diagrams in fenced code blocks (notably on Windows) by scoping a system monospace font stack to pre in markdown.css, instead of IBM Plex Mono for those blocks.

The override only redefines --font-ibm-plex-mono inside pre, so inline code and the rest of the UI still use Plex. @node-core/ui-components is bumped 1.7.2 → 1.7.3 for the release.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.56%. Comparing base (2335df8) to head (976454f).
⚠️ Report is 5 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #9015   +/-   ##
=======================================
  Coverage   74.55%   74.56%           
=======================================
  Files         100      100           
  Lines        8801     8803    +2     
  Branches      325      324    -1     
=======================================
+ Hits         6562     6564    +2     
  Misses       2235     2235           
  Partials        4        4           

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[Copilot]

Pull request overview

This PR adjusts Markdown fenced code block typography so box-drawing/ASCII-art diagrams render with consistent character widths on Windows by switching those blocks to a system monospace font stack (instead of IBM Plex Mono) via a scoped CSS variable override.

Changes:

• Override --font-ibm-plex-mono within pre to a system monospace stack to avoid per-glyph fallback width mismatches on Windows.
• Add detailed rationale in markdown.css explaining the box-drawing glyph issue and why the override is scoped to pre.

---

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[github-actions]

📦 Build Size Comparison

Summary

Metric	Value
Old Total First Load JS	10.64 MB
New Total First Load JS	10.64 MB
Delta	0 B (0.00%)

[avivkeller]

@bmuenzenmeyer can you bump ui-components up a patch