Responsive Component using CSS Flexbox

Hey, awesome work on this one. The overall layout of the site I think looks fine, just needed for the box-shadow to be smoother, currently it has this solid shadow.

Others already gave their feedback on this one which is nice, just going to add some suggestions as well:

• Avoid using height: 100% or height: 100vh on a large container like the body as this makes the element's height capped based on the viewport/screen's height. Instead use min-height: 100vh so that the element will expand if it needs to.
• Always have a main element to wrap the main content of the site. For this use main tag on the .card-underlay1 selector.
• For the .attribution, it would be nice to replace the div with a footer tag so that it will be its own landmark element.
• For the image's interactivity, since it is treated as an interactive component because of the hover effect right, it would be really great to have an interactive element alongside with it. You can use button if you think clicking the image would show a pop-up where the user can see the full nft or an a tag if you think clicking the image would take a user in another page to view the full nft. I haven't made this one yet so I can't provide a reference on it, sorry for this one, but I hope you kind of get the gist of what I said:>
• The overlay-image when hovering on the nft image should be hidden since it is only a decorative image. Decorative images should be hidden for screen-reader at all times by using alt="" and aria-hidden="true" to the img tag or only aria-hidden="true" if you are using svg instead of img tag.
• For the nft name, again it is being treated as an interactive component right, nesting the h1 test inside of an a tag would be really nice:

h1
  a: text in here

• Also just saw the alt for the clock-icon. When using img tag, you don't need to add words that relates to "graphic" such as "icon" and others, since img is already an image so no need to describe it as one.
• On an image, using img tag, if you think that the image is meaningful and really adds content to the site, then use a meaningful alt value. But if the image is just acting decoration, then hide it using the method I mentioned above.
• For the person's image, you can just use the person's name as the only alt value and you can remove the other text inside it.
• Lastly, the person's name is interactive as well. Instead of using bold tag (b) use a tag to wrap the person's name.

Aside from those, great job again on this one.

To be honest the design is not clear, but I think using box-shadow instead of container with background color would be a better implementation of that darker tone that is around the card.

Regarding your question on BEM, this is a resource shared by frontend mentor you should definitely read. It has been explained very well and its benefits as well. BEM resource by frontend mentor.

Updated code files and hosted website with the suggestions made! There's yet a problem with the "a" tag inside the collection image, i can't seem to change its dimensions so it takes the same amount of space the image does (to cover it all)...