:root {
  /* ---------- Colors ---------- */
  --lesson-collection-title-color: #1e3a8a;      /* rich blue */
  --lesson-collection-title-shadow: 2px 2px 6px rgba(0, 0, 0, 0.1);
  
  /* ---------- Font ---------- */
  --lesson-collection-title-font: 'Poppins', 'Segoe UI', Tahoma, sans-serif;
  
  /* ---------- Font Sizes ---------- */
  --lesson-collection-title-size: 3rem;
  --lesson-collection-title-size-mobile: 2rem;
  
  /* ---------- Spacing ---------- */
  --lesson-collection-gap: 20px;
  --lesson-collection-padding: 30px 20px;
}

.lesson_collection {
  padding: var(--lesson-collection-padding);
  margin-bottom: 40px;
  text-align: center;
}

.lesson_collection_title {
  font-family: var(--lesson-collection-title-font);
  font-size: var(--lesson-collection-title-size);
  font-weight: 700;
  color: var(--lesson-collection-title-color);
  text-shadow: var(--lesson-collection-title-shadow);
  margin: 0;
  line-height: 1.2;
  transition: transform 0.3s ease, color 0.3s ease;
}

.lesson_collection_title:hover {
  color: #4f46e5; /* subtle hover color */
  transform: scale(1.05);
}

/* Responsive for mobile */
@media (max-width: 600px) {
  .lesson_collection_title {
    font-size: var(--lesson-collection-title-size-mobile);
  }
}