max(3vw, 20pt) My maximum size is 3vw and my minimum size is 20pt

max(2vw, 16pt) My maximum size is 2vw and my minimum size is 16pt

Resize the viewport to see the effect

max(1.5rem, 3cqi) My maximum size is 1.5rem and my minimum size is 3cqi

max(1rem, 2.25cqi) My maximum size is 1rem and my minimum size is 2.25cqi

Resize the viewport to see the effect