/* ========================
   pdf-library-page.css — Стили для PDF библиотеки
   ========================
   Этот файл содержит:
   - Фильтры (в т.ч. sticky)
   - Сетка PDF материалов
   - Адаптивность
   ======================== */

/* ========================
   1. Фильтры
   ======================== */

.pdf-library-page__filters {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  align-items: flex-end;
}

.pdf-library-page__filter {
  flex: 1;
  min-width: 200px;
}

.pdf-library-page__filter label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

/* ========================
   2. Sticky фильтры (опционально)
   ======================== */

.pdf-library-page__filters-sticky {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  padding: 1rem 16px;
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
  margin: -16px -16px 1.5rem -16px;
}

/* ========================
   3. Сетка PDF материалов
   ======================== */

.pdf-library-page__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
  gap: 1.5rem;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 16px;
}

/* ========================
   4. Пустое состояние
   ======================== */

.lectures-page__empty {
  text-align: center;
  padding: 3rem;
  color: var(--color-text-secondary);
}

/* ========================
   5. Цветные бейджи для дисциплин
   ======================== */

.pdf-library-page__grid .content-card__badge--mathematics:hover {
  background: linear-gradient(135deg, #bbdefb 0%, #90caf9 100%);
  color: #0d47a1;
}

.pdf-library-page__grid .content-card__badge--physics:hover {
  background: linear-gradient(135deg, #c8e6c9 0%, #a5d6a7 100%);
  color: #1b5e20;
}

.pdf-library-page__grid .content-card__badge--chemistry:hover {
  background: linear-gradient(135deg, #f8bbd0 0%, #f48fb1 100%);
  color: #880e4f;
}

.pdf-library-page__grid .content-card__badge--special:hover {
  background: linear-gradient(135deg, #ffe0b2 0%, #ffcc80 100%);
  color: #e65100;
}

.page-section__subtitle {
  text-align: center;
}