How do I make the "added to cart" notification opaque?

[nialovemore]

on my website, when you add something to the cart and you get the cart drop down notification, it is transparent and thus is very hard to read. How can I make it have a background that is black?  ive tried some other solution and they didnt word for me, i assume because im using more of a custom theme 

Thank you

https://nialovemore.com/products/dark-angel-sticker

pass: fairy

[Kyle_liu]

Hi @nialovemore 

I found a video added to the background of the webpage. Can you consider removing this video?