:root {
  font-family: -apple-system, -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  font-size: 15px;
  line-height: 1.6;
  margin: 0;
  --root-padding: 24px;
  padding: 0 var(--root-padding);
  background: white;
}

body {
  margin: 0;
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

header {
  margin-bottom: 1em;
}

main {
  flex: 1;
  border: 1px dashed blue;
  padding: 1em;
}

footer {
  text-align: center;
  border-top: 1px solid gray;
  margin: 30px calc(-1 * var(--root-padding)) 0;
  padding: var(--root-padding);
}

h1,
h2 {
  line-height: 1.3em;
  margin: 0.5rem 0 0.75rem;
  font-weight: normal;
}

#console {
  position: relative;
  border: 1px solid gray;
  border-radius: 4px;
  padding: 0.5rem;
  margin: 2em 0;
  white-space: pre;
  font-family: monospace;
  min-height: 2rem;
}

#console::before {
  content: "Error Console";
  display: inline-block;
  position: absolute;
  top: 0;
  left: 0.1em;
  background: white;
}

:focus {
  outline: 1px solid green;
}