body {
  padding: min(5vw, 50px);
}

#content .preview section {
  margin: 10px;
  font-family: Courier, monospace;
}

#content .preview section span hr {
  outline: none;
  border: none;
  transition-duration: 200ms;
  margin: 0px;
  opacity: 0;
  border-bottom: 4px dashed #0d6efd;
}

#content .preview section span:hover hr {
  opacity: 1;
}