swoon.css

html {
  font: max(3ch, 5vmax + 3vmin) sans-serif;
}

body {
  display: flex;
  flex-flow: anywhere;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
  overflow-wrap: anywhere;
  margin: 0;
  min-height: 100vh;
}

body > * {
  box-sizing: border-box;
  padding: 1ch;
}

h1 {
  font-weight: unset;
  justify-content: center;
  animation: 60s ease-in-out swoon infinite;
  margin: auto;
}

p {
  margin: auto;
}

a {
  display: inline-flex;
  padding: 1vmin;
}

b {
  text-shadow:
    0 -3vh 0,
    0 -2vh 0,
    0 -1vh 0;
}

body {
  display: flex;
  flex-flow: column;
  margin: auto;
}

main {
  align-items: center;
  display: flex;
  flex-flow: row;
  justify-content: center;
  min-height: 100vh;
}

:root {
  background: #ee1;
  color: indigo;
  background-image: radial-gradient(#ee1, gainsboro);
}

:any-link {
  background: darkviolet;
  color: #ee1;
}

::selection {
  background: hotpink;
  color: indigo;
}

@keyframes swoon {
  from {
    text-shadow: 0 -1vh 0 mediumpurple;
  }

  to {
    text-shadow: 0 -1vh 0 darkviolet;
  }
}

:focus-within {
  box-shadow: 0 0 0 50vw deepskyblue;
}

:focus {
  box-shadow: 0 0 0 30vmax mediumpurple;
  outline: thick outset;
}