(the bookmark bar works fine as well, it's just retracted in the screenshot)
Download this file, and follow this guide to install it.
I'm pretty sure you also need the irixium skin for kde for this to work properly.
This skin requires the window decoration to be separate, so turn on the titlebar (right click blank space next to tabs -> customize toolbar -> check titlebar in the bottom left of the screen)
I have the css hardcoded to use the SE98 icon for the bookmark folders from a nonstandard location, (ctrl f "SE98" in the css), so if you want the folder icons to work get the icon pack and edit the part of the CSS to point to the SE98 icon location on your computer