Sticky positioning in CSS is used to position elements in a specific area and they “stick” there while you scroll. It is usually used for things like navigation menus, headings, etc. Here’s how to use it:
1. Assign the `position: sticky;` line to the CSS class or ID of the element you want to stick.
```
.sticky-element {
position: -webkit-sticky; /* For Safari */
position: sticky;
}
```
1. Add a `top` or `bottom` line defining where you want the top (or bottom) edge of the sticky element to “stick” to its nearest ancestor that’s not a body. This can be in `px`, `%`, `rem`, `vh`, etc.
```
.sticky-element {
position: -webkit-sticky; /* For Safari */
position: sticky;
top: 0; /* 0 px from the top of the viewport */
}
```
1. For `position: sticky;` to work, the sticky element needs to be inside an overflow area. This means that in case the sticky element’s parent has `overflow: hidden;`, `position: sticky;` will not work.
1. Another important thing to remember is that sticky elements stick to their nearest positioning ancestor (not always directly the parent), so you need to be aware of the bigger picture to make sure it works as you want.
1. Lastly, `position: sticky;` doesn’t work in all browsers, so it’s very useful to provide a fallback by using other positioning values.
```
.sticky-element {
position: -ms-extend; /* For Edge */
position: -webkit-sticky; /* For Safari */
position: sticky;
top: 0;
}
```
Remember to test `position: sticky;` thoroughly in your layout, as it can have unexpected results depending on the parent elements and their positioning rules.
