.theorem-box {
  border: 1.5px solid #1b5e20;
  border-radius: 8px;
  margin: 1.2em 0;
  overflow: hidden;
  font-family: "Latin Modern Roman", "Computer Modern", Georgia, serif;
}
.theorem-head {
  background: #1b5e20;
  color: #fff;
  font-weight: bold;
  padding: 0.5em 1em;
}
.theorem-body {
  background: #f1f8e9;
  padding: 0.8em 1em;
  color: #1a1a1a;
}
.theorem-body p:last-child { margin-bottom: 0; }