Search results
People also ask
What is CSS flex layout?
What are Flexbox layout modes?
What are Flexbox layouts?
What is Flexbox in HTML?
Block, for sections in a webpage. Inline, for text. Table, for two-dimensional table data. Positioned, for explicit position of an element. The Flexible Box Layout Module, makes it easier to design flexible responsive layout structure without using float or positioning.
- Tryit Editor V3.6
The W3Schools online code editor allows you to edit code and...
- CSS Flex Container
Example. The column-reverse value stacks the flex items...
- Tryit Editor V3.6
- display. This defines a flex container; inline or block depending on the given value. It enables a flex context for all its direct children. .container { display: flex; /* or inline-flex */ }
- flex-direction. 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.
- flex-wrap. 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. .container { flex-wrap: nowrap | wrap | wrap-reverse; }
- flex-flow. This is a shorthand for the flex-direction and flex-wrap properties, which together define the flex container’s main and cross axes. The default value is row nowrap.
The flex layout provides an efficient and flexible way to layout, align, and distribute the space between the elements within a container. In this tutorial, you will learn about CSS flex layout and the different terminologies associated with flex-based layouts.
- Overview
- The two axes of flexbox
- Start and end lines
- The flex container
- Multi-line flex containers with flex-wrap
- The flex-flow shorthand
- Properties applied to flex items
- Alignment, justification and distribution of free space between items
- Next steps
The flexible box layout module, usually referred to as flexbox, was designed as a one-dimensional layout model, and as a method that could offer space distribution between items in an interface and powerful alignment capabilities. This article gives an outline of the main features of flexbox, which we will be exploring in more detail in the rest of these guides.
When we describe flexbox as being one-dimensional we are describing the fact that flexbox deals with layout in one dimension at a time — either as a row or as a column. This can be contrasted with the two-dimensional model of CSS Grid Layout, which controls columns and rows together.
When working with flexbox you need to think in terms of two axes — the main axis and the cross axis. The main axis is defined by the flex-direction property, and the cross axis runs perpendicular to it. Everything we do with flexbox refers back to these axes, so it is worth understanding how they work from the outset.
Another vital area of understanding is how flexbox makes no assumption about the writing mode of the document. In the past, CSS was heavily weighted towards horizontal and left-to-right writing modes. Modern layout methods encompass the range of writing modes and so we no longer assume that a line of text will start at the top left of a document and run towards the right-hand side, with new lines appearing one under the other.
You can read more about the relationship between flexbox and the Writing Modes specification in a later article; however, the following description should help explain why we do not talk about left and right and top and bottom when we describe the direction that our flex items flow in.
If the flex-direction is row and I am working in English, then the start edge of the main axis will be on the left, the end edge on the right.
If I were to work in Arabic, then the start edge of my main axis would be on the right and the end edge on the left.
In both cases the start edge of the cross-axis is at the top of the flex container and the end edge at the bottom, as both languages have a horizontal writing mode.
After a while, thinking about start and end rather than left and right becomes natural, and will be useful to you when dealing with other layout methods such as CSS Grid Layout which follow the same patterns.
An area of a document that is laid out using flexbox is called a flex container. To create a flex container, set the area's display property to flex. When we do this, the direct children of that container become flex items. You can explicitly control whether the container itself is displayed inline or in block formatting context using inline flex or inline-flex for inline flex containers or block flex or flex for block level flex containers.
As with all properties in CSS, some initial values are defined, so the contents of a new flex container will behave in the following way:
•Items display in a row (the flex-direction property's default is row).
•The items start from the start edge of the main axis.
•The items do not stretch on the main dimension but can shrink.
•The items will stretch to fill the size of the cross-axis.
While flexbox is a one dimensional model, it is possible to cause our flex items to wrap onto multiple lines. In doing so, you should consider each line as a new flex container. Any space distribution will happen across that line, without reference to the lines on either side.
To cause wrapping behavior add the property flex-wrap with a value of wrap. Now, should your items be too large to all display in one line, they will wrap onto another line. The live sample below contains items that have been given a width, the total width of the items being too wide for the flex container. As flex-wrap is set to wrap, the items wrap. Set it to nowrap, which is also the initial value, and they will instead shrink to fit the container because they are using initial flexbox values that allows items to shrink. Using nowrap would cause an overflow if the items were not able to shrink, or could not shrink small enough to fit.
You can combine the two properties flex-direction and flex-wrap into the flex-flow shorthand. The first value specified is flex-direction and the second value is flex-wrap.
In the live example below try changing the first value to one of the allowable values for flex-direction - row, row-reverse, column or column-reverse, and also change the second to wrap and nowrap.
To have more control over flex items we can target them directly. We do this by way of three properties:
•flex-grow
•flex-shrink
•flex-basis
We will take a brief look at these properties in this overview, and you can gain a fuller understanding in the guide Controlling Ratios of Flex Items on the Main Axis.
Before we can make sense of these properties we need to consider the concept of available space. What we are doing when we change the value of these flex properties is to change the way that available space is distributed amongst our items. This concept of available space is also important when we come to look at aligning items.
align-items
The align-items property will align the items on the cross axis. The initial value for this property is stretch and this is why flex items stretch to the height of the flex container by default. This might be dictated by the height of the tallest item in the container, or by a size set on the flex container itself. You could instead set align-items to flex-start in order to make the items line up at the start of the flex container, flex-end to align them to the end, or center to align them in the center. Try this in the live example — I have given the flex container a height in order that you can see how the items can be moved around inside the container. See what happens if you set the value of align-items to: •stretch •flex-start •flex-end •center
justify-content
The justify-content property is used to align the items on the main axis, the direction in which flex-direction has set the flow. The initial value is flex-start which will line the items up at the start edge of the container, but you could also set the value to flex-end to line them up at the end, or center to line them up in the center. You can also use the value space-between to take all the spare space after the items have been laid out, and share it out evenly between the items so there will be an equal amount of space between each item. To cause an equal amount of space on the right and left of each item use the value space-around. With space-around, items have a half-size space on either end. Or, to cause items to have equal space around them use the value space-evenly. With space-evenly, items have a full-size space on either end. Try the following values of justify-content in the live example: •flex-start •flex-end •center •space-around •space-between •space-evenly
justify-items
The justify-items property is ignored in flexbox layouts.
After reading this article you should have an understanding of the basic features of flexbox. In the next article, we will look at how this specification relates to other parts of CSS.
Example. The column-reverse value stacks the flex items vertically (but from bottom to top): .flex-container { display: flex; flex-direction: column-reverse; } Try it Yourself »
5 days ago · Flexbox is a one-dimensional layout method for arranging items in rows or columns. Items flex (expand) to fill additional space or shrink to fit into smaller spaces. This article explains all the fundamentals. Why flexbox? CSS flexible box layout enables you to: Vertically center a block of content inside its parent.
Apr 28, 2021 · Watch on. First, What is Flexbox? When you're building a house, you need a blueprint. In the same way, we need a blueprint when we're making websites. And Flexbox is the blueprint. The Flexbox model allows us to layout the content of our website.
