How to specify size

css class description
w-25 The width is 25% of the parent's width.
w-50 The width is 50% of the parent's width.
w-75 The width is 75% of the parent's width.
w-100 The width is 100% of the parent's width.
w-auto Width auto.
h-25 The height is 25% of the parent's height.
h-50 The height is 50% of the parent's height.
h-75 The height is 75% of the parent's height.
h-100 The height is 100% of the parent's height.
h-auto height auto.
mw-100 Max width is the parent's width.
mh-100 Max height is the parent's height.
vw-100 Width is equal to width of viewport.
vh-100 Height is equal to height of viewport.
min-vw-100 Minimum width is equal to width of viewport.
min-vh-100 Minimum height is equal to height of viewport.