CSS Flexible Box Layout (Flexbox) Dynamic Vertical and Horizontal Centering (align-items, justify-content)
Example
Simple Example (centering a single element)
HTML
<div class="aligner">
<div class="aligner-item">…</div>
</div>
CSS
.aligner {
display: flex;
align-items: center;
justify-content: center;
}
.aligner-item {
max-width: 50%; /*for demo. Use actual width instead.*/
}
Here is a demo.
Reasoning
| Property | Value | Description |
|---|---|---|
align-items | center | This centers the elements along the axis other than the one specified by flex-direction, i.e., vertical centering for a horizontal flexbox and horizontal centering for a vertical flexbox. |
justify-content | center | This centers the elements along the axis specified by flex-direction. I.e., for a horizontal (flex-direction: row) flexbox, this centers horizontally, and for a vertical flexbox (flex-direction: column) flexbox, this centers vertically) |
Individual Property Examples
All of the below styles are applied onto this simple layout:
<div id="container">
<div></div>
<div></div>
<div></div>
</div>
where #container is the flex-box.
Example: justify-content: center on a horizontal flexbox
CSS:
div#container {
display: flex;
flex-direction: row;
justify-content: center;
}
Outcome:
Here is a demo.
Example: justify-content: center on a vertical flexbox
CSS:
div#container {
display: flex;
flex-direction: column;
justify-content: center;
}
Outcome:
Here is a demo.
Example: align-content: center on a horizontal flexbox
CSS:
div#container {
display: flex;
flex-direction: row;
align-items: center;
}
Outcome:
Here is a demo.
Example: align-content: center on a vertical flexbox
CSS:
div#container {
display: flex;
flex-direction: column;
align-items: center;
}
Outcome:
Here is a demo.
Example: Combination for centering both on horizontal flexbox
div#container {
display: flex;
flex-direction: row;
justify-content: center;
align-items: center;
}
Outcome:
Here is a demo.
Example: Combination for centering both on vertical flexbox
div#container {
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
}
Outcome:
Here is a demo.
