CSS

html {
  max-width: 70ch;
  padding: 3em 1em;
  margin: auto;
  line-height: 1.75;
  font-size: 1.25em;
}

h1,h2,h3,h4,h5,h6 {
  margin: 3em 0 1em;
}

p,ul,ol {
  margin-bottom: 2em;
  color: #1d1d1d;
  font-family: sans-serif;
}

div {
  display: flex
  justify-content: center
  align-items: center
}

div {
  display: grid
  place-items: center
}