/* Style for theorem environments */
.theorem, .lemma, .proposition, .corollary {
  border-left: 4px solid #ef3be0;
  padding: 10px 15px;
  margin: 15px 0;
}

.proof {
  border-left: 4px solid #94989d;
  padding: 10px 15px;
  margin: 15px 0;
}

.example {
  border-left: 4px solid #6b8e23;
  padding: 10px 15px;
  margin: 15px 0;
}

.exercise {
  border-left: 4px solid #efb550;
  padding: 10px 15px;
  margin: 15px 0;
}