/* サンプル本の読み物ページ（/sample）
   LP本体（style.css）と同じ配色を使い、読むことだけに絞った版。
   ・本文は最大 42rem。長い1ページなので目次から各章へ飛べる
   ・画像はタップで拡大（manual-library と同じ作り）
   ・横スクロールを絶対に起こさない（生URL等が無くても overflow-wrap は保険で入れる） */

:root {
  --navy: #121f38;
  --navy-2: #203456;
  --gold: #d7b55d;
  --gold-dark: #9b7728;
  --ink: #142033;
  --muted: #59657a;
  --line: rgba(215, 181, 93, 0.34);
  --ivory: #fbf7ec;
  --white: #ffffff;
  --shadow: 0 24px 72px rgba(16, 28, 50, 0.16);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
  scroll-padding-top: 64px;
}

body.bk {
  margin: 0;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--ivory);
  font-family: "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.95;
  line-break: strict;
  word-break: auto-phrase;
  overflow-wrap: anywhere;
  text-wrap: pretty;
  -webkit-text-size-adjust: 100%;
}

img { display: block; width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }

/* ── ヘッダー ─────────────────────────────── */
.bk-head {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(251, 247, 236, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.bk-back {
  display: block;
  max-width: 42rem;
  margin: 0 auto;
  padding: 14px 20px;
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--muted);
}

.bk-back:hover { color: var(--gold-dark); }

main { max-width: 42rem; margin: 0 auto; padding: 0 20px 80px; }

/* ── 表紙 ─────────────────────────────────── */
.bk-hero { padding: 36px 0 8px; text-align: center; }

.bk-badge {
  display: inline-block;
  margin: 0 0 22px;
  padding: 7px 18px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  color: var(--gold-dark);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.bk-cover {
  max-width: 260px;
  margin: 0 auto 26px;
  border-radius: 6px;
  box-shadow: var(--shadow);
}

.bk-hero h1 {
  margin: 0 0 8px;
  font-size: 1.42rem;
  line-height: 1.6;
  color: var(--navy);
}

.bk-sub { margin: 0 0 18px; color: var(--muted); font-size: 0.95rem; }

.bk-meta {
  margin: 0 0 6px;
  color: var(--gold-dark);
  font-size: 0.86rem;
  font-weight: 700;
}

.bk-note { margin: 0; color: var(--muted); font-size: 0.76rem; line-height: 1.8; }

/* ── 目次 ─────────────────────────────────── */
.bk-toc {
  margin: 34px 0 10px;
  padding: 24px 24px 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--white);
}

.bk-toc h2 {
  margin: 0 0 14px;
  font-size: 0.94rem;
  letter-spacing: 0.18em;
  color: var(--gold-dark);
}

.bk-toc ol { margin: 0; padding: 0; list-style: none; counter-reset: toc; }

.bk-toc li { counter-increment: toc; border-top: 1px solid rgba(215, 181, 93, 0.2); }
.bk-toc li:first-child { border-top: 0; }

.bk-toc a {
  display: block;
  padding: 12px 0;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--navy);
}

.bk-toc a:hover { color: var(--gold-dark); }

/* ── 本文 ─────────────────────────────────── */
.bk-chapter { padding: 46px 0 10px; }

.bk-chapter h2 {
  margin: 0 0 30px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--line);
  font-size: 1.24rem;
  line-height: 1.55;
  color: var(--navy);
}

.bk-chapter h3 {
  margin: 44px 0 20px;
  font-size: 1.06rem;
  line-height: 1.65;
  color: var(--navy-2);
}

.bk-chapter p {
  margin: 0 0 1.5em;
  font-size: 1rem;
  line-height: 1.95;
}

.bk-chapter figure {
  margin: 30px 0 34px;
  padding: 0;
}

.bk-chapter figure img {
  border-radius: 6px;
  box-shadow: 0 14px 40px rgba(16, 28, 50, 0.12);
  cursor: zoom-in;
}

/* ── 最後のCTA ────────────────────────────── */
.bk-cta {
  margin: 60px 0 0;
  padding: 40px 28px;
  border-radius: 12px;
  background: var(--navy);
  color: var(--white);
  text-align: center;
}

.bk-cta h2 { margin: 0 0 16px; font-size: 1.18rem; line-height: 1.6; }
.bk-cta p { margin: 0 0 26px; font-size: 0.94rem; line-height: 1.9; opacity: 0.9; }

.bk-btn {
  display: inline-block;
  padding: 16px 34px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  color: var(--navy);
  font-weight: 700;
  font-size: 1rem;
  box-shadow: 0 16px 40px rgba(117, 87, 25, 0.32);
}

/* ── 画像の拡大（ライトボックス）──────────── */
.bk-lightbox {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: #000;
}

.bk-lb-stage {
  position: absolute;
  inset: 0;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #000;
}

.bk-lb-stage img { width: 100%; max-width: 900px; }

.bk-lb-close {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 2;
  width: 44px;
  height: 44px;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
  font-size: 1.1rem;
  cursor: pointer;
}

@media (max-width: 640px) {
  main { padding: 0 16px 64px; }
  .bk-hero h1 { font-size: 1.24rem; }
  .bk-chapter h2 { font-size: 1.14rem; }
  .bk-chapter p { font-size: 1.02rem; }
  .bk-toc { padding: 20px 18px 14px; }
  .bk-cta { padding: 32px 20px; }
}

/* ── ジャンル選択の一覧（/sample）─────────────────────────
   2026-08-10 追加。本が増えたらカードが増えるだけで済む作り */
.bk-head-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  max-width: 42rem;
  margin: 0 auto;
  padding: 0 20px;
}

.bk-head-inner .bk-back {
  padding: 14px 0;
}

.bk-back--sub {
  color: var(--gold-dark);
  font-weight: 700;
}

.bk-index-hero {
  padding: 44px 0 10px;
  text-align: center;
}

.bk-index-hero h1 {
  margin: 0 0 16px;
  font-size: 1.5rem;
  line-height: 1.6;
  color: var(--navy);
}

.bk-index-lead {
  max-width: 34rem;
  margin: 0 auto;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.9;
}

.bk-index-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
  gap: 22px;
  margin: 34px 0 10px;
}

.bk-card {
  display: flex;
  flex-direction: column;
  padding: 22px 22px 24px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--white);
  box-shadow: 0 12px 34px rgba(16, 28, 50, 0.08);
  transition: transform 0.28s ease, box-shadow 0.28s ease;
}

.bk-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 22px 54px rgba(16, 28, 50, 0.16);
}

.bk-card-cover {
  display: block;
  max-width: 190px;
  margin: 0 auto 20px;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 14px 38px rgba(16, 28, 50, 0.18);
}

.bk-card-cover img {
  display: block;
  width: 100%;
  height: auto;
}

.bk-card-body {
  display: block;
  text-align: center;
}

.bk-card-genre {
  display: inline-block;
  margin-bottom: 12px;
  padding: 5px 16px;
  border-radius: 999px;
  background: var(--navy);
  color: var(--white);
  font-size: 0.78rem;
  font-weight: 700;
}

.bk-card-title {
  display: block;
  margin-bottom: 10px;
  font-size: 1.04rem;
  font-weight: 700;
  line-height: 1.6;
  color: var(--navy);
}

.bk-card-note {
  display: block;
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.8;
}

.bk-card-meta {
  display: block;
  margin-bottom: 18px;
  color: var(--gold-dark);
  font-size: 0.8rem;
  font-weight: 700;
}

.bk-card-btn {
  display: block;
  padding: 13px 20px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  color: var(--navy);
  font-size: 0.94rem;
  font-weight: 700;
  box-shadow: 0 12px 30px rgba(117, 87, 25, 0.26);
}

.bk-cta-sub {
  margin: 22px 0 0;
  font-size: 0.88rem;
}

.bk-cta-sub a {
  color: var(--gold);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.bk-br-sp { display: none; }

@media (max-width: 640px) {
  .bk-br-sp { display: inline; }
  .bk-index-hero h1 { font-size: 1.3rem; }
  .bk-head-inner { padding: 0 16px; }
  .bk-card { padding: 20px 18px 22px; }
}