table,
tr,
th,
td,
caption {
  border: 2px solid black;
  font-family: "Courier New", Courier, monospace;
  border-collapse: collapse;
  padding: 0.5rem;
}

body {
   background-image: url(img/booksbackground.png);
}
tr:nth-child(2n) {
  background-color: gray;
}