fix: Chrome draws the popup in its monospace font (closes #418)

Chrome adds a stylesheet of its own to extension pages that sets the font
on body. Tailwind 4 puts its classes in a cascade layer, and a rule outside
any layer wins over them, so font-mono lost and Chrome drew the popup in
the system font. body now carries font-mono!, which marks the class
important. Both end-to-end suites check the popup's font.

The same stylesheet also makes Chrome draw the popup's text at 12px rather
than text-sm's 14px; that is unchanged here and filed as issue 456.

Model: opus-5-5

TODO.md

@@ -45,6 +45,16 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-05: Chrome draws the popup in its monospace font
+  ([#418](https://git.eeqj.de/sneak/AutistMask/issues/418)), as Firefox does.
+  Chrome adds a stylesheet of its own to extension pages that sets the font on
+  `body`, and it beat Tailwind's `font-mono`: Tailwind 4 puts its classes in a
+  cascade layer, and a rule outside any layer wins over them. `body` now carries
+  `font-mono!`, which marks the class important. Both end-to-end suites check
+  the popup's font. The same stylesheet also makes Chrome draw the popup's text
+  at 12px rather than the 14px `text-sm` asks for; that is unchanged, and filed
+  as [#456](https://git.eeqj.de/sneak/AutistMask/issues/456).
+
 - 2026-10-05: Dead code removed and copied view helpers shared
   ([#168](https://git.eeqj.de/sneak/AutistMask/issues/168)). AddressDetail and
   AddressToken each defined their own `isoDate()` and `timeAgo()` in place of