Some classes not being detected in source files with square brackets

[caleb]

Versions:

@tailwindcss/cli: 4.0.8
tailwindcss: 4.0.8

Build tool: None
Node Version: v23.7.0
Browser: N/A
OS: macOS (15.3.1)
Reproduction URL: https://github.com/caleb/tailwindcss4bug

Issue
Tailwind is not dectecting a class when it's in a source file with a specific layout.

Let's say we have a component that has this code:

["h-[calc(100vh-(var(--spacing)*8)-(var(--spacing)*14))]",
 true],

Tailwind 4 will not detect the height class (version 3 did), and it won't include it in the output css file.

If we have either of these other layouts, then it does detect the class and generates the appropriate CSS:

["h-[calc(100vh-(var(--spacing)*8)-(var(--spacing)*14))]", true],

[ "h-[calc(100vh-(var(--spacing)*8)-(var(--spacing)*14))]",
 true],

[philipp-spiess]

Hey! Thanks for the repro. We're working on some larger scale changes to our scanner logic and have made sure to include your test case there as well 👍 We'll update you when we we're closer to shipping these fixes.

[RobinMalfait]

Hey!

This should be fixed and will be available in the next release. You can already try it if you want using the insiders version:

• npm install tailwindcss@insiders @tailwindcss/cli@insiders
• npm install tailwindcss@insiders @tailwindcss/postcss@insiders
• npm install tailwindcss@insiders @tailwindcss/vite@insiders

[caleb]

Thanks!