YouTube Overlay Opacity Reducer od Adrian Nightsong

A Firefox extension that reduces the opacity of YouTube overlay elements for a less intrusive viewing experience while maintaining full functionality on hover.

The extension intelligently targets specific YouTube overlay elements and reduces their opacity to your preferred level (default 30%). When you hover your mouse over any transparent element, it instantly returns to full visibility, allowing you to interact with it normally. Move your mouse away, and it fades back to your set transparency level.