Perspective dynamic font sizing

[schenk]

You're missing the multiplication operator in the calc function. It should be this:
calc(0.5*(1.0vmin + 1.0vmax))
calc(3.0*(1.0vmin + 1.0vmax))

Here is some documentation

[nminchin]

Update:

I've actually converted back to rem units with orientation media queries for font sizes, as the calc with vmin/vmax fails with portrait displays like mobiles.

e.g.