Utility classes to provide an easy way to adjust the layout of the elements. 
Utilities for all things related to size. 
Position
  Top / Right / Bottom / Left
  top-{value} / right-{value} / bottom-{value}
		/ left-{value}
 Uses same length variables mentioned at .
  Flex
 Flex Direction
  Flex Grow & Shrink
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
		15.
  Align Items
  | Class | Properties | 
|---|
 | items-auto | align-items: auto | 
 | items-start | align-items: flex-start | 
 | items-end | align-items: flex-end | 
 | items-center | align-items: center | 
 | items-stretch | align-items: stretch | 
  Justify Content
  | Class | Properties | 
|---|
 | justify-start | justify-content: flex-start | 
 | justify-center | justify-content: center | 
 | justify-end | justify-content: flex-end | 
 | justify-between | justify-content: space-between | 
 | justify-around | justify-content: space-around | 
 | justify-evenly | justify-content: space-evenly | 
  Align Self
  | Class | Properties | 
|---|
 | self-auto | align-self: auto | 
 | self-start | align-self: flex-start | 
 | self-end | align-self: flex-end | 
 | self-center | align-self: center | 
 | self-stretch | align-self: stretch | 
  Align Content
  | Class | Properties | 
|---|
 | align-auto | align-content: auto | 
 | align-start | align-content: flex-start | 
 | align-end | align-content: flex-end | 
 | align-center | align-content: center | 
 | align-stretch | align-content: stretch |