html, body {
  min-height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding: 0;
  margin: 0;
  background: navy;
  margin: 10px;
  gap: 10px;
}

pre {
  padding: 8px;
  border-radius: 5px;
  margin: 0;
  overflow-x: auto;
}

pre.cyan {
 background: cyan;
}

pre.green {
  background: lightgreen;
}