body {
  margin: 10px;
  padding: 0;
  font-family: Arial, sans-serif;
  overflow: hidden;
}
pre {
  font-family: Arial, sans-serif;
}

/* scroll */
#top {
  padding: 5px;
  height: 90vh;
  width: 100%;
  background-color: white;
  overflow-y: scroll;
}
.userinput {
  background-color: #f1f1f1;
}
#bottom {
  height: 10vh;
  margin-top: 5px;
}