This text has a font size of 20px at viewport width of 768px and font size of 36px when viewport width is 1920px. But if the viewport width is less than 768px, the font-size won't get lower than 16px and if the viewport width is more than 1920px font size will stop scaling at 48px.

16px ------- <768px

20px ------- 768px - 1919px

36px ------- 1920px

48px ------- 1920px>