:root {
  --edge-bg: #f5f5f3;
  --edge-stage: #d8d4ce;
  --edge-surface: #ffffff;
  --edge-text: #1a1a1a;
  --edge-muted: #666666;
  --edge-accent: #8b7355;
  --edge-accent-light: #c4a574;
  --edge-border: #e5e2dc;
  --edge-paper: #faf8f5;
  --edge-serif: Georgia, "Noto Serif TC", "Songti TC", serif;
  --edge-sans: system-ui, "PingFang TC", "Microsoft JhengHei", sans-serif;
  --edge-shadow-page: 0 8px 32px rgba(0, 0, 0, 0.12);
  --edge-shadow-soft: 0 2px 12px rgba(0, 0, 0, 0.08);
}

.reader-body {
  margin: 0;
  overflow: hidden;
  background: var(--edge-bg);
  color: var(--edge-text);
  font-family: var(--edge-sans);
  -webkit-font-smoothing: antialiased;
}

.reader-app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
}

.reader-toolbar {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
  height: 4.5rem;
  padding: 0 1.25rem;
  background: var(--edge-surface);
  border-bottom: 1px solid var(--edge-border);
  z-index: 20;
}

.reader-toolbar__back {
  color: var(--edge-accent);
  text-decoration: none;
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  flex-shrink: 0;
  transition: color 0.2s;
}

.reader-toolbar__back:hover {
  color: var(--edge-text);
}

.reader-toolbar__brand {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  line-height: 0;
}

.reader-toolbar__brand img {
  height: 2rem;
  width: auto;
}

.reader-toolbar__title {
  font-family: var(--edge-serif);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--edge-muted);
  flex-shrink: 0;
}

.reader-toolbar__pages {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--edge-accent);
  flex: 1;
  min-width: 0;
}

.reader-toolbar__actions {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.reader-btn {
  border: 1px solid var(--edge-accent-light);
  background: var(--edge-surface);
  color: var(--edge-accent);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1;
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.reader-btn:hover {
  color: var(--edge-text);
  border-color: var(--edge-accent);
  background: var(--edge-paper);
}

.reader-btn--link {
  text-decoration: none;
  display: inline-flex;
  align-items: center;
}

.reader-stage {
  position: relative;
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--edge-stage);
}

.reader-app.is-thumbs-open .reader-stage {
  padding-bottom: var(--reader-thumbs-h, 0px);
  box-sizing: border-box;
  align-items: stretch;
}

.reader-app.is-thumbs-open .reader-viewport {
  flex: 1 1 0;
  min-height: 0;
  height: auto;
}

.reader-viewport {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  touch-action: none;
}

.reader-zone {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 28%;
  border: none;
  background: transparent;
  cursor: pointer;
  z-index: 12;
  padding: 0;
}

.reader-zone--prev {
  left: 0;
}

.reader-zone--next {
  right: 0;
}

.reader-pan {
  position: relative;
  z-index: 1;
  transform-origin: center center;
  pointer-events: none;
}

.reader-book {
  position: relative;
  perspective: 2800px;
  perspective-origin: 50% 50%;
  transform-style: preserve-3d;
  overflow: visible;
}

.reader-book,
.reader-book * {
  pointer-events: auto;
}

.reader-slot .mag-page img {
  image-rendering: auto;
}

.reader-spread {
  position: relative;
  display: flex;
  align-items: stretch;
  gap: 0;
  transform-style: preserve-3d;
  transition: opacity 0.08s ease;
}

.reader-spread::before {
  content: "";
  position: absolute;
  inset: -10px;
  background: rgba(250, 248, 245, 0.22);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.08s ease;
  z-index: 2;
}

.reader-spread::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 34px;
  transform: translateX(-50%);
  background: linear-gradient(
    to right,
    rgba(0, 0, 0, 0.14) 0%,
    rgba(0, 0, 0, 0.03) 28%,
    rgba(255, 255, 255, 0.16) 52%,
    rgba(0, 0, 0, 0.06) 100%
  );
  opacity: 0.45;
  pointer-events: none;
  z-index: 3;
}

.reader-spread--single {
  justify-content: center;
}

.reader-spread--single::after {
  opacity: 0;
}

.reader-spread--single .reader-slot--left {
  display: none;
}

.reader-slot {
  width: var(--page-w);
  height: var(--page-h);
  flex-shrink: 0;
  position: relative;
  z-index: 1;
  box-shadow: var(--edge-shadow-page);
  transform-style: preserve-3d;
  background: var(--mag-paper);
  overflow: hidden;
  transition: box-shadow 0.2s ease, filter 0.2s ease;
}

.reader-slot--empty {
  visibility: hidden;
  box-shadow: none;
}

.reader-slot.is-turning {
  pointer-events: none;
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.08);
  filter: saturate(0.98);
}

.reader-slot .mag-page {
  width: 100%;
  height: 100%;
  margin: 0;
  break-after: auto;
  page-break-after: auto;
  transition: opacity 0.08s ease;
}

.reader-app.is-flipping .reader-spread {
  opacity: 0.82;
}

.reader-app.is-flipping .reader-spread::before {
  opacity: 1;
}

.reader-app.is-flipping .reader-slot .mag-page {
  opacity: 0.92;
}

.reader-flip {
  position: absolute;
  top: 0;
  width: var(--page-w);
  height: var(--page-h);
  transform-style: preserve-3d;
  pointer-events: none;
  z-index: 20;
  will-change: transform, filter;
  overflow: hidden;
  isolation: isolate;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

.reader-flip__sheet {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  overflow: hidden;
}

.reader-flip__sheet::before,
.reader-flip__sheet::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 5;
}

.reader-flip--from-right .reader-flip__sheet::before {
  background: linear-gradient(
    to left,
    rgba(0, 0, 0, 0.2) 0%,
    rgba(0, 0, 0, 0.08) 14%,
    transparent 34%,
    transparent 100%
  );
}

.reader-flip--from-left .reader-flip__sheet::before {
  background: linear-gradient(
    to right,
    rgba(0, 0, 0, 0.2) 0%,
    rgba(0, 0, 0, 0.08) 14%,
    transparent 34%,
    transparent 100%
  );
}

.reader-flip__sheet::after {
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0.16) 0%,
    transparent 18%,
    transparent 82%,
    rgba(0, 0, 0, 0.08) 100%
  );
}

.reader-flip__face {
  position: absolute;
  inset: 0;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  overflow: hidden;
  box-shadow: var(--edge-shadow-page);
  transform-style: preserve-3d;
}

.reader-flip__face--front {
  transform: rotateY(0deg) translateZ(1px);
}

.reader-flip__face--front .mag-page {
  width: 100%;
  height: 100%;
  margin: 0;
}

.reader-flip__face--back {
  transform: rotateY(180deg) translateZ(1px);
}

.reader-flip__face--back.reader-flip__face--paper {
  background: linear-gradient(
    145deg,
    #ebe6df 0%,
    var(--edge-paper) 42%,
    #e5e0d8 100%
  );
  box-shadow: inset 0 0 40px rgba(0, 0, 0, 0.05);
}

.reader-flip__face--back.reader-flip__face--paper::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to left,
    rgba(0, 0, 0, 0.06) 0%,
    transparent 18%,
    transparent 82%,
    rgba(0, 0, 0, 0.04) 100%
  );
  pointer-events: none;
}

.reader-flip__face--back .mag-page {
  width: 100%;
  height: 100%;
  margin: 0;
}

.reader-flip--from-right {
  right: 0;
  transform-origin: left center;
}

.reader-flip--from-left {
  left: 0;
  transform-origin: right center;
}

.reader-nav {
  position: absolute;
  top: 0;
  bottom: 0;
  width: min(18vw, 120px);
  border: none;
  background: transparent;
  cursor: pointer;
  z-index: 15;
  padding: 0;
  transition: transform 0.18s ease, opacity 0.2s ease;
}

.reader-nav::before,
.reader-nav::after {
  position: absolute;
  pointer-events: none;
}

.reader-nav::before {
  top: 50%;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  background: rgba(250, 248, 245, 0.84);
  color: var(--edge-accent);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.12);
  font-family: var(--edge-serif);
  font-size: 1.9rem;
  line-height: 1;
  transform: translateY(-50%) scale(0.94);
  opacity: 0.24;
  transition: opacity 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.reader-nav::after {
  content: "";
  top: 0;
  bottom: 0;
  width: 100%;
  opacity: 0.45;
  transition: opacity 0.2s ease;
}

.reader-nav--prev {
  left: 0;
}

.reader-nav--prev::before {
  content: "‹";
  left: 16px;
}

.reader-nav--prev::after {
  left: 0;
  background: linear-gradient(to right, rgba(0, 0, 0, 0.12) 0%, transparent 72%);
}

.reader-nav--next {
  right: 0;
}

.reader-nav--next::before {
  content: "›";
  right: 16px;
}

.reader-nav--next::after {
  right: 0;
  background: linear-gradient(to left, rgba(0, 0, 0, 0.12) 0%, transparent 72%);
}

.reader-nav:hover::before,
.reader-nav:focus-visible::before {
  opacity: 1;
  transform: translateY(-50%) scale(1);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.16);
}

.reader-nav:hover::after,
.reader-nav:focus-visible::after,
.reader-app.is-flipping .reader-nav::after {
  opacity: 0.72;
}

.reader-app.is-flipping .reader-nav {
  pointer-events: none;
}

.reader-thumbs {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  max-height: 42vh;
  background: var(--edge-surface);
  border-top: 1px solid var(--edge-border);
  box-shadow: 0 -8px 32px rgba(0, 0, 0, 0.08);
  z-index: 30;
  display: flex;
  flex-direction: column;
}

.reader-thumbs[hidden] {
  display: none;
}

.reader-thumbs__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--edge-accent);
  border-bottom: 1px solid var(--edge-border);
}

.reader-thumbs__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
  gap: 10px;
  padding: 12px 14px 16px;
  overflow-y: auto;
  background: var(--edge-bg);
}

.reader-thumb {
  border: 2px solid transparent;
  background: none;
  padding: 0;
  cursor: pointer;
  border-radius: 2px;
  overflow: hidden;
  box-shadow: var(--edge-shadow-soft);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.reader-thumb:hover {
  border-color: var(--edge-accent-light);
}

.reader-thumb.is-active {
  border-color: var(--edge-accent);
  box-shadow: 0 4px 16px rgba(139, 115, 85, 0.2);
}

.reader-thumb__frame {
  width: 100%;
  aspect-ratio: 702 / 900;
  overflow: hidden;
  pointer-events: none;
  background: var(--mag-paper);
}

.reader-thumb__frame .mag-page {
  width: var(--page-w);
  height: var(--page-h);
  margin: 0;
  pointer-events: none;
}

.reader-status {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  margin: 0;
  padding: 12px 20px;
  background: var(--edge-surface);
  color: var(--edge-text);
  border: 1px solid var(--edge-border);
  border-radius: 6px;
  box-shadow: var(--edge-shadow-page);
  font-size: 0.875rem;
  z-index: 40;
  pointer-events: none;
}

.reader-status.is-hidden {
  display: none;
}

.reader-app.is-ready .reader-status {
  display: none;
}

.reader-coach {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}

.reader-coach[hidden] {
  display: none;
}

.reader-coach__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(26, 26, 26, 0.55);
  cursor: pointer;
}

.reader-coach__panel {
  position: relative;
  z-index: 1;
  width: min(20rem, calc(100vw - 2.5rem));
  padding: 1.5rem 1.25rem 1.25rem;
  background: var(--edge-surface);
  border-radius: 12px;
  box-shadow: var(--edge-shadow-page);
  pointer-events: auto;
}

.reader-coach__list {
  list-style: none;
  margin: 0 0 1.25rem;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1.125rem;
}

.reader-coach__item {
  display: flex;
  align-items: center;
  gap: 0.875rem;
}

.reader-coach__icon {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  color: var(--edge-accent);
}

.reader-coach__text {
  font-size: 0.9375rem;
  line-height: 1.45;
  color: var(--edge-text);
}

.reader-coach__dismiss {
  display: block;
  width: 100%;
  text-align: center;
}

.reader-coach__print-spot {
  position: fixed;
  z-index: 2;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.reader-coach__print-spot[hidden] {
  display: none;
}

.reader-coach__print-highlight {
  width: 100%;
  box-sizing: border-box;
  border: 2px solid var(--edge-accent-light);
  border-radius: 999px;
  box-shadow: 0 0 0 4px rgba(196, 165, 116, 0.25);
  background: rgba(255, 255, 255, 0.12);
}

.reader-coach__print-finger {
  flex-shrink: 0;
  margin-top: 6px;
  font-size: 2.75rem;
  line-height: 1;
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.45));
  animation: reader-coach-finger-tap 1.2s ease-in-out infinite;
}

.reader-coach__icon--emoji {
  font-size: 2rem;
  line-height: 1;
  width: 3rem;
  height: 3rem;
}

@keyframes reader-coach-finger-tap {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-6px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .reader-coach__print-finger {
    animation: none;
  }
}

@media (max-width: 768px) {
  .reader-toolbar {
    height: 3.5rem;
    padding: 0 0.75rem;
    gap: 10px;
  }

  .reader-toolbar__brand img {
    height: 1.625rem;
  }

  .reader-toolbar__title {
    display: none;
  }

  .reader-toolbar__actions .reader-btn:not(#btn-thumbs):not(#btn-print) {
    display: none;
  }

  .reader-nav {
    width: 56px;
  }

  .reader-nav::before {
    width: 38px;
    height: 38px;
    font-size: 1.45rem;
  }

  .reader-nav--prev::before {
    left: 8px;
  }

  .reader-nav--next::before {
    right: 8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .reader-flip {
    transition: none !important;
  }
}