:root {
  --highlight: #fef9c2;
  --sans-serif:
    -apple-system, BlinkMacSystemFont, avenir next, avenir, segoe ui,
    helvetica neue, Adwaita Sans, Cantarell, Ubuntu, roboto, noto, helvetica,
    arial, sans-serif;
  --serif:
    Iowan Old Style, Apple Garamond, Baskerville, Times New Roman, Droid Serif,
    Times, Source Serif Pro, serif, Apple Color Emoji, Segoe UI Emoji,
    Segoe UI Symbol;
  --mono:
    Menlo, Consolas, Monaco, Adwaita Mono, Liberation Mono, Lucida Console,
    monospace;
}

body {
  margin: 1rem auto;
  max-width: 36rem;
  padding: 0 0.5rem 1rem;
  font-family: var(--sans-serif);
  font-size: 1rem;
  line-height: 1.75;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.2;
}

a {
  color: var(--link);
}

img {
  max-width: 100%;
  height: auto;
}

mark {
  background-color: var(--highlight);
}