You can create a sticky header using the CSS property “position: sticky”. This property is used to create elements that stick to the viewport’s top as you scroll.
For example:
HTML:
```
CSS:
```
header {
position: sticky;
top: 0;
height: 50px;
color: white;
background-color: black;
}
```
This CSS will ensure that your header remains stuck to the top of your viewport and remains visible as you scroll down. The “top: 0” makes sure the header sticks to the top. If you wanted your header to stick only after a certain scrolling amount, you could adjust this number.
Please note that position: sticky might not support some old browsers. For wider browser support, JavaScript should be used.
Another important note is that a sticky positioning context is created by the nearest ancestor with a “transform”, “perspective”, or “filter” property set to something other than “none”. That means, if your header’s parent has one of these properties set, your header might behave unexpectedly. You can usually get around this by setting the parent element’s property to “none”.
