Flex Direction

# Row
flex-row

## horizontal positioning
[] []

# Column
flex-col

## vertical positioning
[]
[]

Center and Wrap

# center vertical and horizontal, wrap
flex justify-center items-center flex-wrap
flex-wrap
flex-nowrap

Z-index

// least priority
className="z-0"

// highest priority
className="z-50"

Padding and Margin

# all four sides
p

# horizontal/vertical symmetric
px
py

# horizontal
pr
pl

# vertical
pt
pb

# number
p-0
p-0.5
p-1
p-1.5
p-2
p-2.5
p-3
p-3.5
p-4
p-5

Placement

# place item 0 px from specified position
top-0
right-0
bottom-0
left-0

# 4 px
top-1
right-1
bottom-1
left-1