I'm noticing a lot of people are using and sharing minified CSS here (meaning, all on one line of text with little or no whitespace)

That's gonna hurt you down the line, because it's really hard to read and edit things with no visible organization, so if your CSS is like that, I'd suggest putting it through a "beautifier" tool like the one here: https://codebeautify.org/css-beautify-minify

I think you'll agree that this (using something from my own CSS as an example):

.card, .card-nest, .card-nest .card:last-child {
  border: none;
}

::selection {
  background-color: #fff;
  color: hsl(0, 0%, 21%);
}

is easier to read than this:

.card,.card-nest,.card-nest .card:last-child{border: none;}::selection{background-color: #fff;color: hsl(0,0%,21%);}