:root {
  --paper: #fbfaf6;
  --paper-deep: #f1eee8;
  --ink: #26313a;
  --muted: #696b6b;
  --line: #cec9bf;
  --accent: #82584f;
  --accent-deep: #684239;
  --serif: "Shippori Mincho", "Yu Mincho", "YuMincho", serif;
  --sans: "Noto Sans JP", "Hiragino Kaku Gothic ProN", sans-serif;
  color-scheme: light;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}
body::before {
  position: fixed;
  inset: 0;
  z-index: 10;
  pointer-events: none;
  content: "";
  opacity: .026;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.78' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
a { color: inherit; }
.skip-link { position: fixed; top: 8px; left: 8px; z-index: 20; padding: 10px 16px; background: var(--ink); color: #fff; transform: translateY(-150%); }
.skip-link:focus { transform: translateY(0); }
.page-shell { width: min(1480px, calc(100vw - 80px)); min-height: 100vh; margin: 0 auto; display: grid; grid-template-rows: auto 1fr auto; }
.site-header { height: 116px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid rgba(206, 201, 191, .72); }
.brand { color: var(--ink); font-size: 27px; letter-spacing: .01em; text-decoration: none; }
.brand strong { font-weight: 600; }
.brand span { color: var(--accent); font-weight: 400; }
.back-link { display: inline-flex; align-items: center; gap: 14px; padding: 11px 0; border-bottom: 1px solid var(--ink); color: var(--ink); font-size: 15px; letter-spacing: .08em; text-decoration: none; }
.back-link svg, .primary-link svg { width: 22px; fill: none; stroke: currentColor; stroke-width: 1.5; transition: transform .2s ease; }
.back-link:hover svg, .back-link:focus-visible svg, .primary-link:hover svg, .primary-link:focus-visible svg { transform: translateX(4px); }
.hero { min-height: 710px; display: grid; grid-template-columns: .88fr 1.12fr; align-items: center; gap: 42px; padding: 54px 2% 70px; overflow: hidden; }
.hero-copy { position: relative; z-index: 2; padding-left: 22px; }
.hero h1 { margin: 0; font-family: var(--serif); font-size: clamp(54px, 5.15vw, 82px); font-weight: 500; line-height: 1.48; letter-spacing: .04em; word-break: keep-all; }
.hero-copy > p:not(.note) { margin: 32px 0 34px; font-size: 16px; line-height: 2.1; letter-spacing: .035em; }
.primary-link { display: inline-flex; min-height: 66px; align-items: center; justify-content: center; gap: 18px; padding: 16px 28px; background: var(--accent); color: #fff; font-weight: 600; letter-spacing: .045em; text-decoration: none; transition: background .2s ease, transform .2s ease; }
.primary-link:hover, .primary-link:focus-visible { background: var(--accent-deep); transform: translateY(-2px); }
.note { margin: 11px 0 0; color: var(--muted); font-size: 12px; letter-spacing: .02em; }
.book-preview { position: relative; min-height: 540px; margin: 0 -3% 0 0; display: grid; place-items: center; perspective: 1200px; }
.book-shadow { position: absolute; width: 76%; height: 22%; bottom: 9%; border-radius: 50%; background: rgba(63, 48, 43, .17); filter: blur(28px); transform: rotate(-3deg); }
.book { position: relative; width: min(680px, 94%); aspect-ratio: 1.35 / 1; display: grid; grid-template-columns: 1fr 1fr; transform: rotate(-2.2deg) rotateY(-2deg); filter: drop-shadow(0 25px 28px rgba(46, 39, 36, .12)); }
.book::after { position: absolute; top: 3%; bottom: 3%; left: 50%; width: 1px; content: ""; background: rgba(95, 83, 74, .22); box-shadow: -7px 0 13px rgba(80, 69, 61, .08), 7px 0 13px rgba(255,255,255,.9); }
.book-page { position: relative; padding: clamp(35px, 4.1vw, 62px); background: #fffefa; border: 1px solid rgba(84, 72, 63, .14); overflow: hidden; }
.book-page-left { border-radius: 4px 0 0 4px; background: linear-gradient(90deg, #fffefa 0%, #fffdf8 82%, #f2eee7 100%); }
.book-page-right { border-radius: 0 4px 4px 0; background: linear-gradient(90deg, #f2eee7 0%, #fffdf8 18%, #fffefa 100%); }
.book-label { margin: 0; color: var(--accent); font-size: 11px; letter-spacing: .2em; }
.book-title { margin: 26% 0 0; font-family: var(--serif); font-size: clamp(26px, 2.5vw, 40px); line-height: 1.7; letter-spacing: .08em; }
.book-mark { position: absolute; left: clamp(35px, 4.1vw, 62px); bottom: 11%; width: 42px; height: 1px; background: var(--accent); }
.book-page ol { margin: 2% 0 0; padding: 0; list-style: none; }
.book-page li { display: grid; grid-template-columns: 45px 1fr; align-items: center; min-height: 82px; border-bottom: 1px solid var(--line); }
.book-page li span { color: var(--accent); font-family: var(--serif); font-size: 16px; }
.book-page li p { margin: 0; font-family: var(--serif); font-size: clamp(16px, 1.5vw, 22px); letter-spacing: .06em; }
.book-caption { margin: 19% 0 0; color: var(--muted); font-family: var(--serif); font-size: clamp(15px, 1.3vw, 19px); line-height: 1.8; text-align: right; }
.thread { position: absolute; right: 10%; bottom: 5%; width: 150px; height: 85px; border: 2px solid rgba(130, 88, 79, .55); border-left-color: transparent; border-bottom-color: transparent; border-radius: 50%; transform: rotate(18deg); }
.site-footer { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 20px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; }

@media (max-width: 900px) {
  .page-shell { width: calc(100vw - 40px); }
  .site-header { height: 90px; }
  .hero { min-height: auto; grid-template-columns: 1fr; gap: 30px; padding: 68px 0 45px; }
  .hero-copy { padding-left: 0; }
  .hero h1 { font-size: clamp(47px, 10vw, 70px); }
  .book-preview { min-height: 500px; margin: 0; }
  .book { width: min(680px, 96%); }
  .site-footer { margin-top: 28px; }
}

@media (max-width: 560px) {
  .page-shell { width: calc(100vw - 28px); }
  .site-header { height: 76px; }
  .brand { font-size: 19px; }
  .back-link { gap: 7px; font-size: 12px; letter-spacing: .02em; }
  .back-link svg { width: 18px; }
  .hero { padding-top: 52px; }
  .hero h1 { font-size: clamp(39px, 11.4vw, 53px); letter-spacing: .02em; }
  .desktop-only { display: none; }
  .hero-copy > p:not(.note) { margin: 25px 0 28px; font-size: 14px; }
  .primary-link { width: 100%; min-height: 62px; padding: 14px 20px; }
  .book-preview { min-height: 330px; }
  .book { width: 104%; transform: rotate(-1deg); }
  .book-page { padding: 22px; }
  .book-title { margin-top: 22%; font-size: 23px; }
  .book-page li { grid-template-columns: 31px 1fr; min-height: 54px; }
  .book-page li span { font-size: 12px; }
  .book-page li p { font-size: 13px; }
  .book-caption { margin-top: 12%; font-size: 12px; }
  .thread { width: 90px; height: 54px; }
  .site-footer { display: block; padding: 22px 0; line-height: 1.8; }
  .site-footer p { margin: 2px 0; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: .01ms !important; }
}