:root {
  --bg-primary: white;
  --bg-secondary: #2a3a60;
  --font-primary: black;
  --font-secondary: #cac3f0;
}

html {
  font-size: 16px;
  color: var(--font-primary);
}

header {
  color: var(--font-secondary);
  background-color: var(--bg-secondary);
}

header a {
  text-decoration: none;
  color: var(--font-secondary);
  font-weight: 600;
}

header h1 {
  text-transform: uppercase;
  margin: 5px auto;
}

header img {
  width: 100%;
}

p {
  font-size: 14px;
  margin: 5px auto;
}

img, nav, p, aside, h1, h2, li {
  padding: 10px;
}

main p, footer p {
  background-color: var(--bg-secondary);
  color: var(--font-secondary);
  margin: 5px auto;
}

footer p, footer h1, footer h2, footer a  {
  font-size: 12px;
  margin: 5px auto;
}

article, section {
  margin: 20px auto;
}

#books {
  width: 100%;
  border-collapse: collapse;
}

td, th {
  border: solid 1px var(--bg-secondary);
  text-align: left;
}

td {
  padding: 8px;
}

th {
  padding: 12px 8px;
  text-align: center;
  background-color: var(--bg-secondary);
  color: var(--font-secondary);
}

tr:nth-child(2n) {
  background-color: gainsboro;
}

tr:hover {
  background-color: blanchedalmond;
}