/* Problem set layout styles extracted from previous inline <style> */
.problem-set-container { padding: 2rem; }
.difficulty-section {
  border: 1px solid #dee2e6;
  border-radius: 0.375rem;
  padding: 1.5rem;
  margin-bottom: 2rem;
  background-color: #f8f9fa;
}
.difficulty-header {
  background-color: #0d6efd;
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  margin-bottom: 1rem;
  font-weight: bold;
}
.difficulty-header.apprentice { background-color: #198754; }
.difficulty-header.journeyman { background-color: #fd7e14; }
.difficulty-header.master { background-color: #dc3545; }
.problem-number {
  background-color: #e9ecef;
  border-radius: 50%;
  width: 2rem;
  height: 2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  margin-right: 0.5rem;
}
.equation-box {
  background-color: #f8f9fa;
  border: 1px solid #dee2e6;
  border-radius: 0.375rem;
  padding: 1rem;
  margin: 0.5rem 0;
  font-family: 'Courier New', monospace;
  text-align: center;
}