/* Kanji・Music・Landscape — Lessons bookshelf & book rooms
   Museum architecture: Bookshelf → Exhibition room → Lesson */

.bookshelf-page {
  --gallery-wall: #171512;
  --gallery-elevated: #1c1915;
  --ivory: #efe9dc;
  --gold: #c9a458;
  --gold-soft: rgba(201, 164, 88, 0.14);
  --ink-soft: #d8d4cb;
  --ink-quiet: #9a958c;
  --ease-museum: 700ms cubic-bezier(0.22, 1, 0.36, 1);
  --ease: 220ms ease;
  color-scheme: dark;
}

.bookshelf-page body,
body.bookshelf-page {
  margin: 0;
  font-family: "Source Sans 3", "Hiragino Sans", "Noto Sans JP", sans-serif;
  font-size: 1.05rem;
  line-height: 1.65;
  color: #f3f1eb;
  background: var(--gallery-wall, #171512);
  -webkit-font-smoothing: antialiased;
}

.bookshelf-page img {
  max-width: 100%;
  height: auto;
  display: block;
}

.bookshelf-page a {
  color: inherit;
}

.bookshelf-page .skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  z-index: 100;
  padding: 0.5rem 0.85rem;
  background: var(--gold);
  color: #171512;
  text-decoration: none;
  border-radius: 2px;
  transition: top var(--ease);
}

.bookshelf-page .skip-link:focus {
  top: 1rem;
}

.bookshelf-page .visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- Shared header ---------- */

.books-header {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  background: linear-gradient(
    180deg,
    rgba(8, 8, 9, 0.72) 0%,
    transparent 100%
  );
}

.books-header--solid {
  position: sticky;
  background: color-mix(in srgb, var(--gallery-wall) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(201, 164, 88, 0.12);
}

.books-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(100% - 2.5rem, 64rem);
  margin: 0 auto;
  min-height: 3.25rem;
  padding: 0.35rem 0;
}

.books-brand {
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--ink-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--ease);
}

.books-brand:hover,
.books-brand:focus-visible {
  color: var(--gold);
}

.books-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.15rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.books-nav a {
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
  text-decoration: none;
  transition: color var(--ease);
}

.books-nav a:hover,
.books-nav a:focus-visible,
.books-nav a[aria-current="page"] {
  color: var(--gold);
}

/* ---------- Bookshelf hero ---------- */

.shelf-hero {
  position: relative;
  min-height: min(100svh, 54rem);
  display: grid;
  align-items: end;
  overflow: hidden;
  background: #0b0b0c;
}

.shelf-hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.shelf-hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 45%;
  transform: scale(1.03);
  animation: shelf-drift 32s ease-in-out infinite alternate;
}

.shelf-hero-veil {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(
      105deg,
      rgba(8, 8, 9, 0.9) 0%,
      rgba(8, 8, 9, 0.62) 36%,
      rgba(8, 8, 9, 0.32) 60%,
      rgba(8, 8, 9, 0.58) 100%
    ),
    linear-gradient(
      180deg,
      rgba(8, 8, 9, 0.4) 0%,
      transparent 30%,
      rgba(8, 8, 9, 0.75) 76%,
      rgba(8, 8, 9, 0.97) 100%
    ),
    radial-gradient(
      ellipse 55% 50% at 22% 70%,
      rgba(31, 58, 46, 0.28),
      transparent 70%
    );
  pointer-events: none;
}

.shelf-hero-inner {
  position: relative;
  z-index: 1;
  width: min(100% - 2.5rem, 40rem);
  margin: 0 auto 0 clamp(1.25rem, 8vw, 7rem);
  padding: clamp(7rem, 16vw, 11rem) 0 clamp(4.5rem, 10vw, 6.5rem);
  text-align: left;
}

.shelf-hero-brand {
  margin: 0 0 1.35rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: clamp(1.05rem, 2.2vw, 1.35rem);
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--gold);
  animation: shelf-rise 1.15s var(--ease-museum) 0.08s both;
}

.shelf-hero-inner h1 {
  max-width: 12ch;
  margin: 0 0 1.2rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: clamp(2.1rem, 5.2vw, 3.35rem);
  font-weight: 400;
  letter-spacing: 0.01em;
  line-height: 1.18;
  color: #f3f1eb;
  text-shadow: 0 2px 28px rgba(0, 0, 0, 0.45);
  animation: shelf-rise 1.15s var(--ease-museum) 0.22s both;
}

.shelf-hero-lead {
  max-width: 28rem;
  margin: 0;
  font-size: clamp(1.02rem, 1.5vw, 1.14rem);
  line-height: 1.7;
  color: color-mix(in srgb, var(--ink-soft) 94%, white);
  text-shadow: 0 1px 16px rgba(0, 0, 0, 0.35);
  animation: shelf-rise 1.15s var(--ease-museum) 0.36s both;
}

.shelf-hero-scroll {
  position: absolute;
  left: clamp(1.25rem, 8vw, 7rem);
  bottom: 1.35rem;
  z-index: 2;
  display: flex;
  align-items: flex-end;
  width: 2rem;
  height: 3rem;
  text-decoration: none;
  opacity: 0.7;
  transition: opacity var(--ease);
}

.shelf-hero-scroll:hover {
  opacity: 1;
}

.shelf-hero-scroll-line {
  display: block;
  width: 1px;
  height: 2.4rem;
  background: linear-gradient(
    180deg,
    transparent,
    color-mix(in srgb, var(--gold) 80%, white)
  );
  animation: shelf-scroll 2.4s ease-in-out infinite;
}

@keyframes shelf-drift {
  from {
    transform: scale(1.03) translate3d(0, 0, 0);
  }
  to {
    transform: scale(1.07) translate3d(1.2%, -1%, 0);
  }
}

@keyframes shelf-rise {
  from {
    opacity: 0;
    transform: translateY(0.9rem);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes shelf-scroll {
  0%,
  100% {
    transform: scaleY(0.55);
    transform-origin: top;
    opacity: 0.35;
  }
  50% {
    transform: scaleY(1);
    transform-origin: top;
    opacity: 1;
  }
}

/* ---------- Catalogue / bookshelf list ---------- */

.shelf-catalogue {
  padding: clamp(4.5rem, 10vw, 7rem) 0 clamp(4rem, 8vw, 6rem);
  background:
    radial-gradient(
      ellipse 80% 35% at 50% 0%,
      rgba(31, 58, 46, 0.18),
      transparent 70%
    ),
    var(--gallery-wall);
}

.shelf-container {
  width: min(100% - 2.5rem, 36rem);
  margin: 0 auto;
}

.shelf-eyebrow {
  margin: 0 0 0.85rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--gold) 78%, transparent);
}

.shelf-catalogue-head {
  margin-bottom: clamp(2.5rem, 5vw, 3.5rem);
}

.shelf-catalogue-head h2 {
  margin: 0 0 0.75rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: clamp(1.55rem, 3vw, 2rem);
  font-weight: 400;
  letter-spacing: 0.03em;
  color: #f3f1eb;
}

.shelf-catalogue-head p {
  margin: 0;
  max-width: 28rem;
  color: var(--ink-quiet);
  font-size: 1.02rem;
  line-height: 1.7;
}

.shelf-continue {
  margin: 0 0 2.25rem;
  padding: 0;
}

.shelf-continue:empty {
  display: none;
}

.shelf-continue a {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.65rem 0;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--gold) 35%, transparent);
  transition: color var(--ease), border-color var(--ease);
}

.shelf-continue a:hover,
.shelf-continue a:focus-visible {
  color: #d8b66a;
  border-bottom-color: var(--gold);
}

.book-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.book-entry {
  border-top: 1px solid rgba(201, 164, 88, 0.14);
}

.book-entry:last-child {
  border-bottom: 1px solid rgba(201, 164, 88, 0.14);
}

.book-entry-link {
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr);
  gap: 1.25rem 1.75rem;
  align-items: baseline;
  padding: 1.55rem 0.15rem;
  text-decoration: none;
  color: inherit;
  /* Gallery lighting — calm, not button-like */
  transition:
    background 240ms ease-out,
    transform 240ms ease-out;
}

.book-entry-link:hover,
.book-entry-link:focus-visible {
  transform: translateY(-2px);
  /* Warm gold on dark paper — keep the shelf dark */
  background: rgba(201, 164, 88, 0.055);
  outline: none;
}

.book-entry-num {
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 0.85rem;
  letter-spacing: 0.22em;
  color: color-mix(in srgb, var(--gold) 80%, transparent);
  transition:
    color 240ms ease-out,
    letter-spacing 240ms ease-out;
}

.book-entry-link:hover .book-entry-num,
.book-entry-link:focus-visible .book-entry-num {
  color: color-mix(in srgb, var(--gold) 92%, white);
  letter-spacing: 0.26em;
}

.book-entry-title {
  margin: 0 0 0.35rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: clamp(1.25rem, 2.4vw, 1.55rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  color: #f3f1eb;
  transition: color 240ms ease-out;
}

.book-entry-link:hover .book-entry-title,
.book-entry-link:focus-visible .book-entry-title {
  color: #faf7f0;
}

.book-entry-range {
  margin: 0 0 0.35rem;
  font-size: 0.98rem;
  letter-spacing: 0.04em;
  color: color-mix(in srgb, var(--ink-soft) 92%, white);
}

.book-entry-meta {
  margin: 0;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: var(--ink-quiet);
  opacity: 0.85;
}

.book-entry-status {
  margin: 0.55rem 0 0;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.book-entry-status--complete {
  color: color-mix(in srgb, var(--gold) 88%, white);
}

.book-entry-status--growing {
  color: color-mix(in srgb, #8fbc8f 55%, var(--ink-quiet));
}

.shelf-library-note {
  margin: 0 0 2.25rem;
  max-width: 32rem;
  font-size: 1.02rem;
  line-height: 1.7;
  color: var(--ink-quiet);
}

.book-entry--growing .book-entry-title {
  color: color-mix(in srgb, #f3f1eb 88%, var(--ink-quiet));
}

/* ---------- Book exhibition room ---------- */

.book-room {
  min-height: 100svh;
  padding-bottom: clamp(4rem, 9vw, 7rem);
  background:
    radial-gradient(
      ellipse 70% 40% at 50% 0%,
      rgba(31, 58, 46, 0.14),
      transparent 65%
    ),
    var(--gallery-wall);
}

.book-room-intro {
  width: min(100% - 2.5rem, 36rem);
  margin: 0 auto;
  padding: clamp(5.5rem, 12vw, 7.5rem) 0 clamp(2.5rem, 5vw, 3.5rem);
}

.book-room-crumb {
  margin: 0 0 1.5rem;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--ink-quiet);
}

.book-room-crumb a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

.book-room-crumb a:hover,
.book-room-crumb a:focus-visible {
  color: var(--gold);
  border-bottom-color: color-mix(in srgb, var(--gold) 45%, transparent);
}

.book-room-eyebrow {
  margin: 0 0 0.75rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 0.78rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--gold) 78%, transparent);
}

.book-room-intro h1 {
  margin: 0 0 0.85rem;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: clamp(2rem, 4.5vw, 2.85rem);
  font-weight: 400;
  letter-spacing: 0.03em;
  color: #f3f1eb;
}

.book-room-lead {
  margin: 0;
  max-width: 28rem;
  color: var(--ink-quiet);
  font-size: 1.05rem;
  line-height: 1.7;
}

.lesson-exhibit {
  list-style: none;
  margin: 0 auto;
  padding: 0;
  width: min(100% - 2.5rem, 28rem);
  display: flex;
  flex-direction: column;
  /* ~35% tighter than first pass — collection still readable as a whole */
  gap: clamp(1.75rem, 3.75vw, 2.6rem);
}

.lesson-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 0.85rem 0.75rem 1.05rem;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
  border-radius: 4px;
  border: 1px solid transparent;
  background: transparent;
  transition:
    transform 240ms ease-out,
    box-shadow 240ms ease-out,
    border-color 240ms ease-out;
}

.lesson-card:hover,
.lesson-card:focus-visible {
  transform: translateY(-2px);
  border-color: rgba(201, 164, 88, 0.16);
  box-shadow: 0 0 28px rgba(201, 164, 88, 0.14);
  outline: none;
}

.lesson-card-art {
  width: min(100%, 17.5rem);
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border-radius: 3px;
  background: #0e0c0a;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.4);
  transition: box-shadow 240ms ease-out;
}

.lesson-card:hover .lesson-card-art,
.lesson-card:focus-visible .lesson-card-art {
  box-shadow:
    0 12px 28px rgba(0, 0, 0, 0.38),
    0 0 22px rgba(201, 164, 88, 0.18);
}

.lesson-card-art img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.lesson-card-art--empty {
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 50% 45%, rgba(201, 164, 88, 0.12), transparent 65%),
    #12100e;
  border: 1px solid rgba(201, 164, 88, 0.18);
}

.lesson-card-art--empty span {
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 2.4rem;
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--gold) 70%, transparent);
}

.lesson-card-label {
  margin: 0;
  font-family: "Shippori Mincho", "Noto Serif JP", serif;
  font-size: 1.15rem;
  font-weight: 400;
  letter-spacing: 0.14em;
  color: #f3f1eb;
  text-align: center;
}

.lesson-card-rule {
  display: block;
  width: 3.5rem;
  height: 1px;
  margin: 0.15rem auto 0;
  background: linear-gradient(
    90deg,
    transparent,
    color-mix(in srgb, var(--gold) 55%, transparent),
    transparent
  );
  opacity: 0.7;
}

.book-room-footer-nav {
  width: min(100% - 2.5rem, 28rem);
  margin: clamp(3.5rem, 8vw, 5.5rem) auto 0;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.88rem;
  letter-spacing: 0.08em;
}

.book-room-footer-nav a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

.book-room-footer-nav a:hover,
.book-room-footer-nav a:focus-visible {
  color: var(--gold);
  border-bottom-color: color-mix(in srgb, var(--gold) 40%, transparent);
}

.book-room-footer-nav a[aria-disabled="true"] {
  opacity: 0.35;
  pointer-events: none;
}

/* ---------- Footer ---------- */

.books-footer {
  border-top: 1px solid rgba(201, 164, 88, 0.1);
  padding: 2.25rem 0 2.5rem;
  background: #0e0c0a;
}

.books-footer-inner {
  width: min(100% - 2.5rem, 64rem);
  margin: 0 auto;
  text-align: center;
}

.books-footer p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--ink-quiet);
}

.books-footer a {
  color: var(--ink-soft);
  text-decoration: none;
}

.books-footer a:hover {
  color: var(--gold);
}

/* ---------- Reveal ---------- */

.bookshelf-page .reveal {
  opacity: 0;
  transform: translateY(1rem);
  transition:
    opacity 0.9s var(--ease-museum),
    transform 0.9s var(--ease-museum);
}

.bookshelf-page .reveal.is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .shelf-hero-media img,
  .shelf-hero-brand,
  .shelf-hero-inner h1,
  .shelf-hero-lead,
  .shelf-hero-scroll-line,
  .lesson-card,
  .book-entry-link,
  .book-entry-num,
  .book-entry-title {
    animation: none !important;
    transition: none !important;
  }

  .shelf-hero-media img {
    transform: none;
  }

  .bookshelf-page .reveal {
    opacity: 1 !important;
    transform: none !important;
  }

  .lesson-card:hover,
  .lesson-card:focus-visible,
  .book-entry-link:hover,
  .book-entry-link:focus-visible {
    transform: none;
  }
}

@media (max-width: 520px) {
  .book-entry-link,
  .book-entry--soon .book-entry-shell {
    grid-template-columns: 3.4rem minmax(0, 1fr);
    gap: 0.85rem 1rem;
  }

  .books-nav {
    gap: 0.35rem 0.85rem;
  }
}