/* ==========================================================
   pages/book.css — 책 상세 (/books/{isbn13}/)
   .book-hero(표지 + 소개) · .board(몇 등 계산기) · .region-card(타일 지도)
   · .groups(주로 빌린 독자) · .rel-tabs(함께 빌린 책)
   ========================================================== */

/* ---------- 책 소개 ---------- */
.book-hero {
  position: relative; overflow: hidden;
  background:
    radial-gradient(600px 300px at 100% 0%, #E6E4FD 0%, rgba(230, 228, 253, 0) 66%),
    linear-gradient(180deg, var(--paper) 0%, #fff 100%);
  border-bottom: 1px solid var(--line-2);
}
.book-hero-grid {
  display: grid; grid-template-columns: auto minmax(0, 1fr); grid-template-areas: "cover head" "body body";
  gap: 16px 18px; align-items: start; padding-top: 20px; padding-bottom: 24px;
}
.bh-cover { grid-area: cover; }
.bh-cover .cover-lg { width: 104px; }
.bh-head { grid-area: head; min-width: 0; }
.bh-body { grid-area: body; min-width: 0; }
.bh-head .page-kicker { font-size: 12.5px; }
.bh-title { font-size: 23px; font-weight: 900; line-height: 1.3; letter-spacing: -.05em; }
.bh-meta { display: flex; flex-wrap: wrap; gap: 2px 0; margin-top: 8px; font-size: 14px; color: var(--ink-2); }
.bh-meta span + span::before { content: "·"; margin: 0 7px; color: var(--ink-4); }
.bh-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.bh-desc { font-size: 15px; line-height: 1.7; color: var(--ink-2); max-width: 40em; }
.bh-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }

/* ---------- 몇 등 계산기 ---------- */
.board { padding: 16px; }
.board-controls { display: grid; gap: 12px; padding-bottom: 14px; border-bottom: 1px solid var(--line-2); }
.board-ctl { display: flex; align-items: center; gap: 10px; min-width: 0; }
.board-label { flex: none; display: inline-flex; align-items: center; gap: 5px; width: 52px; font-size: 13px; font-weight: 800; color: var(--ink-3); }
.board-label .ico { color: var(--brand); }
.board-ctl .select { min-width: 140px; }
.board-ctl .chips { min-width: 0; }
.board-result { padding: 22px 4px 18px; text-align: center; }
.board-result.swap-in > * { animation: fade-up .3s var(--ease) both; }
.bd-scope { display: inline-flex; align-items: center; gap: 6px; height: 30px; padding: 0 12px; border-radius: 999px; background: var(--brand-soft); color: var(--brand-deep); font-size: 13.5px; font-weight: 800; }
.bd-big { margin-top: 10px; font-size: 22px; font-weight: 800; color: var(--ink-2); line-height: 1.1; letter-spacing: -.04em; }
.bd-big b { font-size: 64px; font-weight: 900; color: var(--navy); letter-spacing: -.06em; font-variant-numeric: tabular-nums; }
.bd-big .bd-out { font-size: 34px; font-weight: 900; color: var(--ink-3); }
.bd-sub { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 6px; margin-top: 10px; font-size: 15px; font-weight: 600; color: var(--ink-2); }
.bd-sub .dl { height: 26px; padding: 0 10px; font-size: 13px; }
.board-facts { display: grid; gap: 6px; }
.board-facts li { display: flex; align-items: center; justify-content: space-between; gap: 10px; min-height: 46px; padding: 0 14px; border-radius: 13px; background: var(--surface-2); }
.board-facts span { display: inline-flex; align-items: center; gap: 7px; font-size: 13.5px; font-weight: 700; color: var(--ink-3); }
.board-facts span .ico { width: 17px; height: 17px; color: var(--ink-4); }
.board-facts b { font-size: 15px; font-weight: 900; letter-spacing: -.02em; }
.board-foot { margin-top: 14px; }

.book-glance { margin-top: 18px; }
.book-sec { margin-top: 44px; }

/* ---------- 지역별 타일 지도 ---------- */
.map-readers { margin-bottom: 16px; }
.map-grid { display: grid; gap: 18px; }
.map-sum { font-size: 15px; font-weight: 600; line-height: 1.6; color: var(--ink-2); }
.map-sum b { font-weight: 900; color: var(--ink); }
.map-side .tmap-legend { margin-top: 12px; }
.map-note { display: flex; gap: 7px; margin-top: 14px; font-size: 12.5px; line-height: 1.6; color: var(--ink-3); }
.map-note .ico { margin-top: 2px; color: var(--ink-4); }

/* ---------- 주로 빌린 독자 ---------- */
.groups { display: grid; gap: 6px; }
.groups li { display: flex; align-items: center; gap: 12px; min-height: 44px; padding: 0 12px; border-radius: 12px; background: var(--surface-2); }
.groups .rk { width: 20px; font-size: 15px; }
.groups b { font-size: 15px; font-weight: 800; }

/* ---------- 함께 빌린 책 ---------- */
.rel-tabs { margin-bottom: 10px; }
.rel-desc { margin-bottom: 16px; font-size: 13.5px; color: var(--ink-3); }
.book-foot { margin-top: 40px; }

@media (min-width: 560px) {
  .bh-cover .cover-lg { width: 132px; }
}
@media (min-width: 768px) {
  .book-hero-grid {
    grid-template-areas: "cover head" "cover body"; grid-template-rows: auto 1fr;
    gap: 14px 36px; padding-top: 32px; padding-bottom: 36px;
  }
  .bh-cover .cover-lg { width: 184px; }
  .bh-title { font-size: 34px; }
  .board { padding: 22px 24px; }
  .board-controls { grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: 16px; }
  .board-label { width: auto; }
  .bd-big b { font-size: 84px; }
  .board-facts { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .board-facts li { display: grid; justify-content: start; gap: 2px; padding: 12px 16px; }
  .map-grid { grid-template-columns: minmax(0, 420px) minmax(0, 1fr); gap: 32px; align-items: center; }
}