[GH-ISSUE #48] custom-ui-style patches break font rendering in markdown preview webviews #34

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opened 2026-05-06 13:12:51 +02:00 by BreizhHardware · 1 comment

BreizhHardware commented

2026-05-06 13:12:51 +02:00

Owner

Originally created by @drewadams on GitHub (Feb 16, 2026).
Original GitHub issue: https://github.com/bwya77/vscode-dark-islands/issues/48

Originally assigned to: @bwya77 on GitHub.

After installing Islands Dark, all markdown preview webviews (both VS Code's built-in markdown preview and Markdown Preview Enhanced) render code blocks in a serif font (Times), ignoring any font-family CSS rules.

Reproduction Steps

Install
Open any markdown file with fenced code blocks
Open the built-in markdown preview (Cmd+Shift+V) or Markdown Preview Enhanced preview
Observe that code blocks render in a serif font (Times) instead of a monospace font

Debugging Details

The font-family CSS rule does apply (confirmed via webview DevTools → Elements → Styles)
document.fonts.check('16px "Fira Code"') returns true in the webview
The Rendered Fonts section in DevTools Computed tab shows Times is being used despite the CSS rule
Both the built-in markdown preview and Markdown Preview Enhanced are affected
Rolling back Custom UI Style fixes the issue and also removes the islands.

Environment

macOS (Apple Silicon)
VS Code 1.108.2
custom-ui-style extension (installed via Islands Dark)

Expected Behavior

Markdown preview webviews should respect font-family CSS rules and render monospace fonts correctly.

Originally created by @drewadams on GitHub (Feb 16, 2026). Original GitHub issue: https://github.com/bwya77/vscode-dark-islands/issues/48 Originally assigned to: @bwya77 on GitHub. After installing Islands Dark, all markdown preview webviews (both VS Code's built-in markdown preview and Markdown Preview Enhanced) render code blocks in a serif font (Times), ignoring any `font-family` CSS rules. ## Reproduction Steps 1. Install 2. Open any markdown file with fenced code blocks 3. Open the built-in markdown preview (`Cmd+Shift+V`) or Markdown Preview Enhanced preview 4. Observe that code blocks render in a serif font (Times) instead of a monospace font ## Debugging Details - The `font-family` CSS rule **does apply** (confirmed via webview DevTools → Elements → Styles) - `document.fonts.check('16px "Fira Code"')` returns `true` in the webview - The **Rendered Fonts** section in DevTools Computed tab shows Times is being used despite the CSS rule - Both the built-in markdown preview and Markdown Preview Enhanced are affected - Rolling back Custom UI Style fixes the issue and also removes the islands. ## Environment - macOS (Apple Silicon) - VS Code 1.108.2 - custom-ui-style extension (installed via Islands Dark) ## Expected Behavior Markdown preview webviews should respect `font-family` CSS rules and render monospace fonts correctly.

BreizhHardware closed this issue

2026-05-06 13:12:51 +02:00

BreizhHardware commented

2026-05-06 13:12:52 +02:00

Author

Owner

@bwya77 commented on GitHub (Feb 19, 2026):

Thanks so much for the really detailed issue description
I resolved this in v.0.0.2

@bwya77 commented on GitHub (Feb 19, 2026): Thanks so much for the really detailed issue description I resolved this in v.0.0.2