:root {
  /* fonts */
  --sans-serif: Seravek, 'Gill Sans Nova', Ubuntu, Calibri, 'DejaVu Sans', source-sans-pro, sans-serif;
  --serif: 'Iowan Old Style', 'Palatino Linotype', 'URW Palladio L', P052, serif;

  /* colors */
  --black: black;
  --blue: hsl(214, 71.2%, 53.7%);
  --dark-grey: rgba(0, 0, 0, 0.7);
  --light-grey: rgba(0, 0, 0, 0.1);
  --medium-grey: rgba(0, 0, 0, 0.5);
  --orange: #ff6300;
  --white: white;

  /* dimensions */
  --max-width: 48rem;
}

* {
  box-sizing: border-box;
}

html,
body {
  font-family: var(--serif);
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--white);
  border-inline-start: 16px solid var(--blue);
  padding: 16px;
}

:any-link {
  color: var(--blue);
  text-decoration: none;
}

:any-link:hover {
  text-decoration: underline;
}

body > header nav {
  font-family: var(--sans-serif);
  margin: 0 auto;
  max-width: var(--max-width);
}

body > header nav :any-link {
  color: var(--black);
  text-decoration: none;
}

body > header nav :any-link:hover {
  text-decoration: underline;
}

main {
  margin: 0 auto;
  max-width: var(--max-width);
  padding: 0;
}

article {
  font-size: 1.25rem;
  line-height: 1.5;
}

article > header {
  border-block-end: 1px solid var(--medium-grey);
  font-family: var(--sans-serif);
}

article > p:first-of-type {
  background-color: var(--light-grey);
  border-radius: 8px;
  padding: 16px;
}

h1 {
  font-size: 3rem;
  line-height: 1.25;
  margin-block-start: 1rem;
  margin-block-end: 0.25rem;
}

h1 :any-link {
  color: var(--black);
}

footer {
  color: var(--dark-grey);
  margin-block-start: 2rem;
}

footer p {
  margin: 0 auto;
  max-width: var(--max-width);
}

.timestamp {
  color: var(--dark-grey);
  font-size: 1rem;
  line-height: 1;
  margin-block-start: 0.25rem;
}

.tldr {
  color: var(--orange);
  font-variant: small-caps;
}

@media (prefers-color-scheme: dark) {
  :root {
    --blue: hsl(214, 71.2%, 68.7%);
    --light-grey: rgba(255, 255, 255, 0.9);
    --medium-grey: rgba(255, 255, 255, 0.5);
  }

  body {
    background-color: var(--black);
    color: var(--white);
  }

  body > header nav :any-link {
    color: var(--white);
  }

  article > header {
    border-color: 
  }

  article > p:first-of-type {
    color: var(--black);
  }

  h1 :any-link {
    color: var(--white);
  }

  footer {
    color: var(--light-grey);
  }

  .timestamp {
    color: var(--light-grey);
  }
}