.left-side {
  width: 50%;
}
.right-side {
  width: 50%;
}
.st-demo-header {
  background-color: #666666;
  color: white;
  font-size: 24px;
  padding: 8px 24px;
}
.st-demo-header button {
  color: black;
  font-size: 12px;
}