angular/aio/content/examples/event-binding/src/app/app.component.css

.group {
  background-color: #dae8f9;
  padding: 1rem;
  margin: 1rem 0;
}

.parent-div {
  background-color: #bdd1f7;
  border: solid 1px rgb(25, 118, 210);
  padding: 1rem;
}

.parent-div:hover {
  background-color: #8fb4f9;
}

.child-div {
  margin-top: 1rem;
  background-color: #fff;
  padding: 1rem;
}

.child-div:hover {
  background-color: #eee;
}