NFT Preview Card

I found it very difficult to build the overlay for the main image: hover state and had to resort to watching a youtube video. I am also unsure about how to use center the card, when I initially put the flex settings in the .container class the layout went wonky , i.e. the page color was not displayed at all, the .container class somehow stretched to fill the entire space on the screen.

It only worked when I put flex settings targetting the body, then everything went well.

I feel like I need more help on how flex works (I will watch youtube videos and make knockoffs of this project to learn) and also learn and understand how position: absolute and relative work.

Please give me feedback on this website, thanks!