body.debug-mode section {
  border: 2px solid red;
}
body.debug-mode article {
  border: 2px solid blue;
}
body.debug-mode header {
  border: 2px solid green;
}
body.debug-mode footer {
  border: 2px solid orange;
}
body.debug-mode .container {
  border: 2px solid purple;
}