Computer line effect

body::before {
  content: " ";
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background: linear-gradient(rgb(0 0 0 / 30%) 50%, rgb(0 0 0 / 0%) 50%);
    background-size: auto;
  z-index: 2;
  background-size: 100% 2px, 3px 100%;
  pointer-events: none;
}

Fonts

For generic fonts (e.g. serif, sans-serif, monospace) you can just use something like this:

body, button, input {
  font-family: monospace;
}

For specific fonts, it needs to be uploaded on a site that allows automated requests from neospring (e.g. catbox.moe), then you can do this:

@font-face {
  font-family: "FontName";
  src: url(https://example.com/FontName.ttf); // replace with your font URL
}

body, button, input {
  font-family: "FontName";
}

Pagedolls, as I've heard them called

nav::before {
  content: '';
  position: fixed;
  bottom: -100px;
  right: -100px;
  width: 400px;
  height: 400px;
  background-image: url(https://example.com/FunnyLittleMan.png); // replace with your image
  background-size: contain;
  background-repeat: no-repeat;
  z-index: 1000;
  pointer-events: none;
}

using nav::before here because I assume you will already be using body::before for the CRT effect. Images must be on a site that allows automated requests (e.g. catbox.moe).

Button borders

I'm not sure what you're asking about here, could you provide an example of a profile that does what you're looking for?

Why you are afraid to ask?

I don't know. But I assure you, you are capable of figuring this out, especially when you have help.

(For the sake of credit, I copied the pagedoll and CRT code from @iris's page, but she did not originate either.)