[laserbeam]

There's a big difference between "mobile first" and "mobile hostile" (even if the hostility is unintentional). Here, for example, the website is just 10-15 characters too wide on mobile, regardless of orientation. It forces you to scroll left and right constantly just to read the lines. And regardless of orientation actually feels hostile, if I flip my phone to landscape, the font size increases and thus I still can't read the whole line.

I agree that designing for mobile first is annoying for the web in general. But... This is text! Most of the website is text, and it doesn't wrap or resize properly for a small screen.

Here, it's likely just a bug with the window width calculation, not a "mobile first" argument.

If a website is 99% text and it can't be read from every screen size from a phone to an ultrawide monitor... Than it's a bug, not a design choice.