These are 100 bytes of CSS that will pretty much make any “vanilla” HMTL look good. I have tested it, and it does look good indeed!
html {
max-width: 70ch;
padding: 3em 1em;
margin: auto;
line-height: 1.75;
font-size: 1.25em;
}
If we add an additional, but optional, 100 bytes—so, 200 bytes in total then—things can get much prettier (this works as a light theme).
h1,h2,h3,h4,h5,h6 {
margin: 3em 0 1em;
}
p,ul,ol {
margin-bottom: 2em;
color: #1d1d1d;
font-family: sans-serif;
}