SM breakpoint is not correct like in the documentation

[Nurai1]

What version of Tailwind CSS are you using?
"tailwindcss": "^4.0.16"

For example: v4.0.6

What build tool (or framework if it abstracts the build tool) are you using?

"vite": "^6.2.3",

What version of Node.js are you using?

v20.10.0

What browser are you using?

Chrome 136.0.7103.93

What operating system are you using?

macOS 15.4.1

Reproduction URL

https://play.tailwindcss.com/vQxilH4Q0w

Describe your issue

SM breakpoint is not correct like in the documentation, docs says it is 640px, actually default is 680px

[Nurai1]

I think it happens because default Chrome 1rem equals to 17px

[wongjn]

Yes, that would be due to your browser font-size settings. The default is 16px but you may have altered your browser settings to be 17px. Also setting html font-size to 17px would also exhibit this behavior.

[Nurai1]

My browser settings really set to 17px, but setting 16px "font-size" to html does not help to set the rem, this is so strange