Viewport-Percentage (or Viewport-Relative) Lengths
Viewport-Percentage Lengths：
The viewport-percentage lengths are relative to the size of the initial containing block. When the height or width of the initial containing block is changed, they are scaled accordingly.
vh(viewport height)vw(viewport width)vmin(viewport minimum length)vmax(viewport maximum length)
What exactly is vmin and vmax?
1vminassumes a value of the smallest between1vhand1vw.-
1vmaxassumes a value of the largest between1vhand1vw.
FROM stackoverflow