Responsive text not working

[Gilead]

I recently started using google fonts for my projects with some success. I'm about to launch a redesigned site only when I checked it under mobile, I saw that text was not scaling as expected. I had used font-size: calc(15px + 1vw); in my css. What am I missing? Thanks!

[Dimitri]

Avoid using mathematical expressions, especially with mixed units. Stick with em, rem, and try to avoid px (for font-size).

[lucy24]

In particular, the locution px + vw seems perilous in the extreme. Why can't you simply leave it at the user's default size--whatever it may be is none of the site owner's business--and use simple percentages for elements that are supposed to be larger or smaller?

If a given font happens to “read” noticeably larger or smaller than an ordinary font of the same type (generally serif or sans-serif), adjust all percentages accordingly. Or, better yet, don't use that particular font ;)

:: pause for irritated mutter that font-size-adjust [caniuse.com] never became standard across all browsers, although it has been around for at least a decade ::