/* ── 책 그리드 ────────────────────────────────────────────────────────── */
.books-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.1rem;
}

/* ── 책 카드 ──────────────────────────────────────────────────────────── */
.book-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.18s, box-shadow 0.18s;
  cursor: pointer;
}
.book-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

/* ── 표지 영역 ────────────────────────────────────────────────────────── */
.book-cover {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  background: #EEE;
}
.book-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s;
}
.book-card:hover .book-cover img { transform: scale(1.04); }

.book-cover-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}
.placeholder-num {
  font-size: 1.8rem;
  font-weight: 700;
  line-height: 1;
}
.placeholder-icon { font-size: 2rem; opacity: 0.7; }

/* ── 책 정보 ──────────────────────────────────────────────────────────── */
.book-info {
  padding: 0.75rem 0.875rem 0.875rem;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.book-title {
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.book-badges { display: flex; flex-wrap: wrap; gap: 0.35rem; margin-top: auto; }

/* ── 배지 ─────────────────────────────────────────────────────────────── */
.badge {
  font-size: 0.7rem;
  font-weight: 500;
  padding: 0.2rem 0.55rem;
  border-radius: 20px;
  white-space: nowrap;
}
.badge-grade   { background: #EBF5FB; color: #2980B9; }
.badge-ready   { background: #EAFAF1; color: #27AE60; }
.badge-pending { background: #F8F9FA; color: #95A5A6; }

/* ── 빈 목록 ──────────────────────────────────────────────────────────── */
.books-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 3rem;
  color: var(--text-muted);
}

/* ── 반응형 ───────────────────────────────────────────────────────────── */
@media (max-width: 600px) {
  .books-grid { grid-template-columns: repeat(2, 1fr); gap: 0.875rem; }
  .book-title { font-size: 0.8rem; }
}
@media (max-width: 360px) {
  .books-grid { grid-template-columns: 1fr; }
}