Let's start with the demo where you can toggle these features on/off:
- transparent scrollbar track
- fix for scrollbar track being too small on tall pages
- use thinner scrollbar track ("middle bar")
- offset for sticky headers
Transparent scrollbar track
Setting the scrollbar (or track) background to transparent won't give you the desired result. In fact it is probably transparent, but what's really going on here is that the page (the html element) is to the left of the scrollbar and not below it. This means we need to find a way to force this, and we can do it by setting
overflow-y: overlay on the html element. This way the main background color of the page stretches to the edge there's no white background below the scrollbar.
Setting scrollbar track minimum height
This was an easy fix that I used in a recent project where a page grew too large, so the scrollbar track was too tiny. I applied
min-height to the track and to my great surprise it worked.
The good thing is that nothing else needs to be modified, the browser automatically figures out offsets and everything, so you can't "overscroll" on the edges.
Thin scrollbar track in the middle
While you can set the desired width of the scrollbar, it will start from the edge. If you would like to apply an offset somehow, you'll see that the usual margin or even transform CSS rules can not be applied here. I figured out that by setting a transparent border together with
background-clip: padding-box does the trick. With this, you can play around with width and border width values to achieve this effect.
The nice thing about this is that you will actually get a transparent padding so the entire scrollbar width is available for dragging with the mouse, not only the thin track bar, which is good in terms of usability.
Fix for sticky headers
The scrollbar is above everything, including sticky headers. If you happen to have such a header and you have set
overflow-y: overlay, then the scrollbar will go on top of the header. But using the technique described above with the thin scrollbar feature you can set a higher border-top width value to make the scrollbar start (and stop) below the sticky header.
This puts a nice final touch on the design, it looks like that the scrollbar belongs to the main page content, excluding the header. Note that this technique makes the scrollbar track appear shorter, which you can fix by setting a higher
With these tips and tricks you can polish the scrollbar design to make it more part of the page and not part of the browser. Even though it's only available in Chromium-based browsers, according to its market share most visitors will see the styled scrollbar.