Flexbox Layout (Flexible Box) module (currently a W3C Last Call Working Draft) aims at providing a more efficient way to lay out, align and distribute space among items in a container, even when their size is unknown and/or dynamic (thus the word "flex").
This defines a flex container; inline or block depending on the given value. It enables a flex context for all its direct children.
This establishes the main-axis, thus defining the direction flex items are placed in the flex container. Flexbox is (aside from optional wrapping) a single-direction layout concept. Think of flex items as primarily laying out either in horizontal rows or vertical columns.
By default, flex items will all try to fit onto one line. You can change that and allow the items to wrap as needed with this property.
This defines the alignment along the main axis. It helps distribute extra free space left over when either all the flex items on a line are inflexible, or are flexible but have reached their maximum size. It also exerts some control over the alignment of items when they overflow the line.
This defines the default behaviour for how flex items are laid out along the cross axis on the current line. Think of it as the
justify-contentversion for the cross-axis (perpendicular to the main-axis).
This aligns a flex container's lines within when there is extra space in the cross-axis, similar to how
justify-content aligns individual items within the main-axis.
By default, flex items are laid out in the source order. However, the
order property controls the order in which they appear in the flex container.
This defines the ability for a flex item to grow if necessary. It accepts a unitless value that serves as a proportion. It dictates what amount of the available space inside the flex container the item should take up.
If all items have
flex-grow set to 1, the remaining space in the container will be distributed equally to all children. If one of the children has a value of 2, the remaining space would take up twice as much space as the others (or it will try to, at least).
This defines the ability for a flex item to shrink if necessary. Negative numbers are invalid.
This defines the default size of an element before the remaining space is distributed. It can be a length (e.g. 20%, 5rem, etc.) or a keyword. The
auto keyword means "look at my width or height property" (which was temporarily done by the
main-size keyword until deprecated). The
content keyword means "size it based on the item's content" - this keyword isn't well supported yet, so it's hard to test and harder to know what its brethren
If set to
0, the extra space around content isn't factored in. If set to
auto, the extra space is distributed based on its
This is the shorthand for
flex-basis combined. The second and third parameters (
flex-basis) are optional. Default is
0 1 auto.
This allows the default alignment (or the one specified by
align-items) to be overridden for individual flex items.
Please see the
align-itemsexplanation to understand the available values.