The original ayuDark theme from https://github.com/maboroshin/qBittorrentDarktheme has following bugs:
You cannot see what is selected. If you hover over an item it is nog highlightd. This has been fixed in ayuDark-fixed-seclected-items.qbtheme.
Additional change: The "black" is actually #000000, fixed in ayuDark-fixed-seclected-items_2.qbtheme.