p.warning::before {
  content: "Warning!";
  display: block;
  font-weight: bold;
  color: #e66;
}

p.important::before {
  content: "Important";
  display: block;
  font-weight: bold;
  color: #c95;
}

div.theorem .name::before {
  content: 'Theorem: ';
  font-weight: bold;
}

div.property .name::before {
  content: 'Property: ';
  font-weight: bold;
}