To make your web-page fonts increase/decrease as the browser window dimensions change use viewport-based values instead of %, ems, pxs or pts.

1vw = 1% of viewport width
1vh = 1% of viewport height
1vmax = 1vw or 1vh, whichever is larger
1vmin = 1vw or 1vh, whichever is smaller

Example:
[…]