/* ============================================================
   BOOKSHELF - Physical bookshelf with book spines & paper sheaves
   ============================================================ */

.bookshelf-section {
  margin-top: 10px;
  margin-bottom: 22px;
  padding: 20px 0 0;
}

/* Side-by-side layout on desktop — no gap so shelves look continuous */
.shelf-row {
  display: flex;
  gap: 0;
}

.shelf-col {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

@media (max-width: 800px) {
  .shelf-row {
    flex-direction: column;
    gap: 8px;
  }
}

.shelf-container {
  position: relative;
  padding: 0 0 12px;
}

/* Shelf label */
.shelf-label {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  padding: 0 16px 4px;
  margin: 8px 0 0;
}

/* ============================================================
   SHARED SHELF BASE
   ============================================================ */
.shelf {
  position: relative;
  padding-bottom: 18px; /* space for plank + lip */
  flex: 1;              /* fill column so both shelves match height */
  display: flex;
  flex-direction: column;
  justify-content: flex-end; /* books sit at the bottom of the shelf */
}

/* Scrollable inner row — only books/papers scroll */
.shelf-scroll {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  padding: 18px 16px 0;  /* top padding accommodates hover lift + shadow */
  overflow-x: auto;
  overflow-y: hidden;
  position: relative;
  z-index: 1;
}

/* Custom scrollbar per shelf */
.shelf-scroll::-webkit-scrollbar {
  height: 6px;
}
.shelf-scroll::-webkit-scrollbar-track {
  background: transparent;
}
.shelf-scroll::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.5);
  border-radius: 999px;
}

/* The wooden shelf plank — stays fixed at the bottom, never scrolls */
.shelf::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 14px;
  background: linear-gradient(180deg, #8B6914 0%, #6B4F12 40%, #5a4210 100%);
  border-radius: 0 0 4px 4px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.15);
  z-index: 4;
}

/* Shelf edge lip — stays fixed */
.shelf::before {
  content: "";
  position: absolute;
  bottom: 14px;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(180deg, #a07d2a, #8B6914);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  z-index: 5;
}

/* Back panel behind items — stays fixed */
.shelf-back {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(180deg,
    rgba(139, 105, 20, 0.05) 0%,
    rgba(139, 105, 20, 0.12) 100%
  );
  border-radius: 4px 4px 0 0;
  z-index: 0;
}

/* Papers shelf */
.shelf.shelf--papers {
  margin-top: 6px;
}

/* Continuous shelf: remove inner border-radius when side-by-side */
@media (min-width: 801px) {
  /* First column — remove right rounding */
  .shelf-col:first-child .shelf::after {
    border-radius: 0 0 0 4px;
  }
  .shelf-col:first-child .shelf-back {
    border-radius: 4px 0 0 0;
  }

  /* Last column — remove left rounding */
  .shelf-col:last-child .shelf::after {
    border-radius: 0 0 4px 0;
  }
  .shelf-col:last-child .shelf-back {
    border-radius: 0 4px 0 0;
  }

  /* Remove papers top margin so shelves align flush */
  .shelf.shelf--papers {
    margin-top: 0;
  }
}

/* ============================================================
   BOOK SPINES - Wider, two-line layout
   ============================================================ */
.book-spine {
  position: relative;
  z-index: 1;
  width: 58px;
  min-width: 48px;
  border-radius: 3px 4px 2px 2px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  text-decoration: none;
  flex-shrink: 0;
}

/* Spine texture overlay */
.book-spine::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(
    90deg,
    rgba(0, 0, 0, 0.15) 0%,
    rgba(255, 255, 255, 0.08) 15%,
    rgba(255, 255, 255, 0.05) 30%,
    transparent 50%,
    rgba(0, 0, 0, 0.05) 85%,
    rgba(0, 0, 0, 0.12) 100%
  );
  pointer-events: none;
  z-index: 1;
}

/* Top/bottom edge shadow for depth */
.book-spine::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.12),
    inset 0 -2px 3px rgba(0, 0, 0, 0.15);
  pointer-events: none;
  z-index: 1;
}

.book-spine:hover {
  transform: translateY(-8px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
  z-index: 10;
}

/* Text container on spine — vertical with wrapping */
.spine-text {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  transform: rotate(180deg);
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 24px 4px 8px;
  overflow: hidden;
  max-height: 100%;
  z-index: 2;
  user-select: none;
  box-sizing: border-box;
}

.spine-title {
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.2;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  /* In vertical-rl, line-clamp works on horizontal overflow */
  white-space: normal;
  word-break: break-word;
}

.spine-author {
  font-size: 0.48rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  line-height: 1.15;
  opacity: 0.75;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ============================================================
   PAPER SHEAVES - Standing upright like stacked pages
   ============================================================ */
.paper-sheaf {
  position: relative;
  z-index: 1;
  width: 52px;
  min-width: 44px;
  border-radius: 1px 2px 1px 1px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  text-decoration: none;
  flex-shrink: 0;
  background: #f5f0e4;
  border: 1px solid rgba(0, 0, 0, 0.1);
}

/* Stacked-pages effect — offset layers behind */
.paper-sheaf::before {
  content: "";
  position: absolute;
  top: 2px;
  left: -3px;
  right: 3px;
  bottom: -1px;
  background: #ece7d8;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 1px;
  z-index: -1;
  transform: rotate(-0.8deg);
}

.paper-sheaf::after {
  content: "";
  position: absolute;
  top: 4px;
  left: -5px;
  right: 5px;
  bottom: -2px;
  background: #e3ddd0;
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 1px;
  z-index: -2;
  transform: rotate(-1.5deg);
}

.paper-sheaf:hover {
  transform: translateY(-8px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
  z-index: 10;
}

/* Text on the paper sheaf — vertical */
.sheaf-text {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  transform: rotate(180deg);
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 22px 5px 8px;
  overflow: hidden;
  max-height: 100%;
  z-index: 2;
  user-select: none;
  color: #2c2c2c;
  box-sizing: border-box;
}

.sheaf-title {
  font-size: 0.52rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.2;
  white-space: normal;
  word-break: break-word;
}

.sheaf-author {
  font-size: 0.44rem;
  font-weight: 400;
  line-height: 1.15;
  opacity: 0.6;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Dog-ear fold on top-right corner */
.paper-sheaf .sheaf-fold {
  position: absolute;
  top: 0;
  right: 0;
  width: 8px;
  height: 8px;
  background: linear-gradient(135deg, transparent 50%, rgba(0,0,0,0.06) 50%);
  z-index: 3;
}

/* ============================================================
   DARK MODE
   ============================================================ */
@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) .shelf::after {
    background: linear-gradient(180deg, #4a3510 0%, #3a2a0d 40%, #2d2008 100%);
  }
  html:not([data-theme="light"]) .shelf::before {
    background: linear-gradient(180deg, #5a4210, #4a3510);
  }
  html:not([data-theme="light"]) .shelf-back {
    background: linear-gradient(180deg,
      rgba(139, 105, 20, 0.03) 0%,
      rgba(139, 105, 20, 0.08) 100%
    );
  }
  html:not([data-theme="light"]) .paper-sheaf {
    background: #2a2520;
    border-color: rgba(255, 255, 255, 0.08);
  }
  html:not([data-theme="light"]) .paper-sheaf::before {
    background: #252018;
    border-color: rgba(255, 255, 255, 0.06);
  }
  html:not([data-theme="light"]) .paper-sheaf::after {
    background: #201c14;
    border-color: rgba(255, 255, 255, 0.04);
  }
  html:not([data-theme="light"]) .sheaf-text {
    color: #d4c9b0;
  }
}

html[data-theme="dark"] .shelf::after {
  background: linear-gradient(180deg, #4a3510 0%, #3a2a0d 40%, #2d2008 100%);
}
html[data-theme="dark"] .shelf::before {
  background: linear-gradient(180deg, #5a4210, #4a3510);
}
html[data-theme="dark"] .shelf-back {
  background: linear-gradient(180deg,
    rgba(139, 105, 20, 0.03) 0%,
    rgba(139, 105, 20, 0.08) 100%
  );
}
html[data-theme="dark"] .paper-sheaf {
  background: #2a2520;
  border-color: rgba(255, 255, 255, 0.08);
}
html[data-theme="dark"] .paper-sheaf::before {
  background: #252018;
  border-color: rgba(255, 255, 255, 0.06);
}
html[data-theme="dark"] .paper-sheaf::after {
  background: #201c14;
  border-color: rgba(255, 255, 255, 0.04);
}
html[data-theme="dark"] .sheaf-text {
  color: #d4c9b0;
}

/* Light mode force (overrides prefers-color-scheme: dark when toggled) */
html[data-theme="light"] .shelf::after {
  background: linear-gradient(180deg, #8B6914 0%, #6B4F12 40%, #5a4210 100%);
}
html[data-theme="light"] .shelf::before {
  background: linear-gradient(180deg, #a07d2a, #8B6914);
}
html[data-theme="light"] .shelf-back {
  background: linear-gradient(180deg,
    rgba(139, 105, 20, 0.05) 0%,
    rgba(139, 105, 20, 0.12) 100%
  );
}
html[data-theme="light"] .paper-sheaf {
  background: #f5f0e4;
  border-color: rgba(0, 0, 0, 0.1);
}
html[data-theme="light"] .paper-sheaf::before {
  background: #ece7d8;
  border-color: rgba(0, 0, 0, 0.08);
}
html[data-theme="light"] .paper-sheaf::after {
  background: #e3ddd0;
  border-color: rgba(0, 0, 0, 0.06);
}
html[data-theme="light"] .sheaf-text {
  color: #2c2c2c;
}

/* Empty shelf message */
.shelf-empty {
  color: var(--muted);
  font-size: 0.9rem;
  font-style: italic;
  padding: 40px 20px;
  text-align: center;
  width: 100%;
}