body {
  background-color: #f8f9fa;
}

.lesson-card {
  cursor: pointer;
}

.lesson-card:hover {
  border-color: #0d6efd;
  transform: translateY(-2px);
  transition: transform 0.2s ease;
}

.study-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.option-btn {
  width: 100%;
  text-align: left;
}

.option-btn.correct {
  background-color: #198754;
  border-color: #198754;
  color: #fff;
}

.option-btn.incorrect {
  background-color: #dc3545;
  border-color: #dc3545;
  color: #fff;
}

.option-btn.disabled-opt {
  pointer-events: none;
  opacity: 0.6;
}