A Comprehensive guide to Flexbox

Flexbox is the one of the most efficient way to align and distribute elements in a container. In CSS every element is a box. Using CSS we can manipulate Outer box properties and Inner box properties. Flexbox is inner property of the box. It can be applied using

.box {
    display: flex;
}

when flex property is applied to a box it changes its inner property and how elements inside the box behaves.

Flexbox Properties

Flex-direction:

This property decides the direction of flex items inside the container

.container {
  flex-direction: row | row-reverse | column | column-reverse;
}

By default containers direction is set to row you can play with this codepen embed given below to understand more about flex direction.

Flex-wrap:

This is to wrap the items in a container by default it is set to no wrap.

.container {
  flex-wrap: nowrap | wrap | wrap-reverse;
}

In this codepen we have set to flex-wrap:wrap; so the elements arranged themselves to the next line automatically.

Justify-content:

This property is used to arrange items in a container

.container {
  justify-content: flex-start | flex-end | center | space-between | space-around | space-evenly | start | end | left | right ;
}

• flex-start` (default): items are packed toward the start of the flex-direction.
• flex-end: items are packed toward the end of the flex-direction.
• start: items are packed toward the start of the writing-mode direction.
• end: items are packed toward the end of the writing-mode direction.
• left: items are packed toward left edge of the container, unless that doesn’t make sense with the flex-direction, then it behaves like start.
• right: items are packed toward right edge of the container, unless that doesn’t make sense with the flex-direction, then it behaves like start.
• center: items are centerd along the line
• space-between: items are evenly distributed in the line; first item is on the start line, last item on the end line
• space-around: items are evenly distributed in the line with equal space around them. Note that visually the spaces aren’t equal, since all the items have equal space on both sides. The first item will have one unit of space against the container edge, but two units of space between the next item because that next item has its own spacing that applies.
• space-evenly: items are distributed so that the spacing between any two items (and the space to the edges) is equal.

align-items:

This property defines how items arranged across the cross axis in the container

.container {
  align-items: stretch | flex-start | flex-end | center | baseline | first baseline | last baseline | start | end | self-start | self-end ;
}

• stretch (default): stretch to fill the container (still respect min-width/max-width)
• flex-start / start / self-start: items are placed at the start of the cross axis. The difference between these is subtle, and is about respecting the flex-direction rules or the writing-mode rules.
• flex-end / end / self-end: items are placed at the end of the cross axis. The difference again is subtle and is about respecting flex-direction rules vs. writing-mode rules.
• center: items are centered in the cross-axis
• baseline: items are aligned such as their baselines align

align-content:

This is like justify-content property but this sets items in cross axis when there is extra space in cross axis

.container {
  align-content: flex-start | flex-end | center | space-between | space-around | space-evenly | stretch | start | end | baseline | first baseline | last baseline;
}

• normal (default): items are packed in their default position as if no value was set.
• flex-start / start: items packed to the start of the container. The (more supported) flex-start honors the flex-direction while start honors the writing-mode direction.
• flex-end / end: items packed to the end of the container. The (more support) flex-end honors the flex-direction while end honors the writing-mode direction.
• center: items centered in the container
• space-between: items evenly distributed; the first line is at the start of the container while the last one is at the end
• space-around: items evenly distributed with equal space around each line
• space-evenly: items are evenly distributed with equal space around them
• stretch: lines stretch to take up the remaining space

Item Properties:

Order:

This is used to change the default order of HTML Content

.item {
  order: -1; /* default is 0 */
}

In this codepen red logos are ordered -1 which is lesser than default so they are pushed to start of the flexbox

flex-grow, flex-shrink, flex-basis:

This property is used to set the space occupied by the elements and negative numbers are not allowed

.item {
/* apply any one property */
  flex-grow: 1;  
  flex-shrink: 1;
  flex-basis: 100px;
}

align-self :

this property allows one specific item to align itself in the container

.item {
  align-self: auto | flex-start | flex-end | center | baseline | stretch;
}