body {
  margin: 0;
  font-size: 16px;
  background-color: #efefef;
  color: #333333;
}

main {
  font-size: 1.2em;
  margin: 1em;
}

header {
  text-align: center;
}

.site-title {
  margin: 0;
}

.morse-call-sign {
  margin: 0.25em;
  display: block;
  font-size: 2em;
}

aside {
  margin: 0 auto;
  max-width: 400px;
}