:root {
  color-scheme: light;
  --ink: #15120d;
  --muted: #615849;
  --paper: #f6efe0;
  --paper-strong: #fff8df;
  --yellow: #f0c92f;
  --yellow-deep: #d79e12;
  --red: #b73124;
  --teal: #0c6a6e;
  --blue-black: #15212a;
  --line: rgba(21, 18, 13, 0.2);
  --shadow: 0 26px 60px rgba(18, 17, 13, 0.22);
  --archive-serif: "SimSun", "Songti SC", Georgia, "Times New Roman", serif;
  --archive-mono: "Courier New", "Lucida Console", "SimSun", monospace;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
  min-height: 100%;
  overflow: hidden;
}

body {
  background:
    radial-gradient(circle at 18% 20%, rgba(86, 55, 24, 0.14), transparent 16%),
    radial-gradient(circle at 74% 84%, rgba(93, 64, 24, 0.12), transparent 18%),
    linear-gradient(90deg, rgba(21, 18, 13, 0.08) 1px, transparent 1px),
    linear-gradient(0deg, rgba(21, 18, 13, 0.055) 1px, transparent 1px),
    image-set(url("archive-paper-texture.webp") type("image/webp"), url("archive-paper-texture.png") type("image/png")),
    #d7c49a;
  background-size: auto, auto, 32px 32px, 32px 32px, cover, auto;
  background-position: center;
  color: var(--ink);
  display: grid;
  place-items: center;
  overflow: hidden;
  position: relative;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

body::before {
  background:
    radial-gradient(circle, rgba(21, 18, 13, 0.38) 0 1px, transparent 1.6px) 6.8% 12% / 10px 10px repeat-y,
    radial-gradient(circle, rgba(21, 18, 13, 0.34) 0 1px, transparent 1.7px) 93.4% 9% / 10px 10px repeat-y,
    linear-gradient(90deg, transparent 0 5.4%, rgba(21, 18, 13, 0.08) 5.45%, transparent 5.7%, transparent 94.1%, rgba(21, 18, 13, 0.075) 94.18%, transparent 94.42%),
    repeating-linear-gradient(90deg, transparent 0 22px, rgba(42, 34, 22, 0.025) 22px 23px),
    repeating-linear-gradient(0deg, transparent 0 17px, rgba(42, 34, 22, 0.018) 17px 18px);
  mix-blend-mode: multiply;
  opacity: 0.72;
}

body::after {
  background:
    radial-gradient(circle at 16% 22%, rgba(173, 32, 22, 0.26) 0 1px, transparent 1.8px),
    radial-gradient(circle at 78% 66%, rgba(12, 106, 110, 0.24) 0 1.2px, transparent 2px),
    repeating-radial-gradient(circle at 73% 18%, rgba(21, 18, 13, 0.12) 0 0.9px, transparent 1px 6px),
    linear-gradient(115deg, rgba(255, 250, 226, 0.18), transparent 30%, rgba(95, 65, 28, 0.1) 100%);
  opacity: 0.36;
  mix-blend-mode: multiply;
}

button,
a {
  font: inherit;
}

a {
  color: inherit;
  text-decoration: none;
}

.archive-shell {
  width: 100vw;
  height: 100vh;
  min-height: 0;
  position: relative;
  display: grid;
  place-items: center;
  padding: 0;
  overflow: hidden;
  z-index: 1;
}

.binding-rail {
  display: none;
}

.binding-rail.compact {
  width: clamp(34px, 4vw, 54px);
}

.binding-rail span {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  margin: 0 auto;
  background: #e9d982;
  box-shadow: inset 0 2px 7px rgba(0, 0, 0, 0.42);
}

.archive-reader {
  width: min(100vw, calc(100vh * 16 / 9));
  height: min(100vh, calc(100vw * 9 / 16));
  min-height: 0;
  aspect-ratio: 16 / 9;
  margin-left: 0;
  padding: clamp(9px, 1.5vmin, 18px);
  background:
    linear-gradient(90deg, rgba(84, 56, 24, 0.09), transparent 12%, transparent 88%, rgba(84, 56, 24, 0.08)),
    repeating-linear-gradient(0deg, rgba(21, 18, 13, 0.026) 0 1px, transparent 1px 28px),
    rgba(242, 229, 196, 0.62);
  border: 1px solid rgba(57, 45, 28, 0.34);
  box-shadow:
    inset 0 0 0 1px rgba(255, 250, 226, 0.34),
    inset 0 0 42px rgba(74, 52, 25, 0.13),
    var(--shadow);
  overflow: hidden;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  position: relative;
}

.archive-reader::before,
.archive-reader::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.archive-reader::before {
  z-index: 0;
  background:
    linear-gradient(90deg, transparent 0 2.2%, rgba(21, 18, 13, 0.16) 2.26%, transparent 2.36%, transparent 97.6%, rgba(21, 18, 13, 0.13) 97.66%, transparent 97.78%),
    radial-gradient(circle at 9% 14%, rgba(91, 62, 31, 0.16), transparent 13%),
    radial-gradient(circle at 92% 84%, rgba(91, 62, 31, 0.13), transparent 16%);
  opacity: 0.78;
  mix-blend-mode: multiply;
}

.archive-reader::after {
  z-index: 0;
  background:
    repeating-linear-gradient(90deg, transparent 0 4px, rgba(21, 18, 13, 0.018) 4px 5px),
    repeating-linear-gradient(0deg, transparent 0 5px, rgba(21, 18, 13, 0.012) 5px 6px);
  opacity: 0.58;
  mix-blend-mode: multiply;
}

.archive-reader > * {
  position: relative;
  z-index: 1;
}

.reader-topline {
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(8px, 1.4vmin, 16px);
  border-bottom: 1px solid rgba(21, 18, 13, 0.72);
  padding: 0 clamp(34px, 3.7vmin, 56px) clamp(4px, 0.8vmin, 8px);
  text-shadow: 0.4px 0 rgba(21, 18, 13, 0.28);
}

.site-mark {
  font-family: var(--archive-serif);
  font-size: clamp(18px, 3vmin, 32px);
  line-height: 0.9;
  font-weight: 900;
  letter-spacing: 0;
  filter: contrast(1.08);
}

.book-kicker {
  color: var(--teal);
  font-family: var(--archive-mono);
  font-weight: 800;
  font-size: clamp(8px, 1.2vmin, 11px);
  letter-spacing: 0;
  text-align: right;
  text-transform: uppercase;
}

.book-layout {
  height: 100%;
  min-height: 0;
  display: grid;
  grid-template-columns: minmax(0, 0.43fr) minmax(0, 0.57fr);
  gap: clamp(8px, 1.8vmin, 18px);
  align-items: stretch;
  padding-top: clamp(6px, 1.3vmin, 14px);
}

.book-panel,
.bound-book-panel,
.zero-index {
  position: relative;
}

.book-panel {
  min-height: 0;
  height: 100%;
  padding: 0;
  background: transparent;
  border: 0;
  box-shadow: none;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
}

.book-panel::before {
  display: none;
}

.book-meta {
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--ink);
  font-family: var(--archive-mono);
  font-size: clamp(8px, 1.1vmin, 11px);
  font-weight: 900;
  letter-spacing: 0;
  border-bottom: 1px solid rgba(21, 18, 13, 0.42);
  margin-left: clamp(18px, 2.4vmin, 34px);
  margin-right: clamp(18px, 2.4vmin, 34px);
  padding-bottom: clamp(3px, 0.7vmin, 6px);
}

.page-stage,
.spread-stage {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  touch-action: none;
  cursor: grab;
  user-select: none;
}

.page-stage:active,
.spread-stage:active {
  cursor: grabbing;
}

.page-stage {
  aspect-ratio: var(--page-ratio, 0.72);
  width: auto;
  height: 100%;
  max-width: 100%;
  min-height: 0;
  justify-self: center;
  align-self: center;
  margin: clamp(4px, 0.8vmin, 8px) auto 0;
  display: grid;
  place-items: center;
  background: transparent;
  border: 0;
  box-shadow: none;
  perspective: 1400px;
}

.page-stage::before,
.page-stage::after,
.spread-stage::before,
.spread-stage::after {
  content: "";
  position: absolute;
  top: 2.5%;
  bottom: 2.5%;
  width: 49.6%;
  background:
    linear-gradient(90deg, rgba(21, 18, 13, 0.11), transparent 8%, transparent 90%, rgba(21, 18, 13, 0.08)),
    #fff9e9;
  box-shadow: 0 18px 38px rgba(21, 18, 13, 0.14);
  z-index: -1;
}

.page-stage::before,
.spread-stage::before {
  left: 0.4%;
  border-radius: 2px 0 0 2px;
}

.page-stage::after,
.spread-stage::after {
  right: 0.4%;
  border-radius: 0 2px 2px 0;
}

.page-stage::before,
.spread-stage::before {
  box-shadow:
    inset -18px 0 28px rgba(21, 18, 13, 0.1),
    0 18px 38px rgba(21, 18, 13, 0.12);
}

.page-stage::after,
.spread-stage::after {
  box-shadow:
    inset 18px 0 28px rgba(21, 18, 13, 0.1),
    0 18px 38px rgba(21, 18, 13, 0.12);
}

.page-stage .pdf-canvas,
.spread-page .pdf-canvas {
  position: relative;
  z-index: 1;
}

.page-stage.is-cover-page .pdf-canvas,
.spread-stage.is-cover-page .pdf-canvas {
  margin-left: auto;
  margin-right: 0.5%;
}

.page-stage.is-cover-page {
  justify-items: end;
  padding-right: 0.5%;
}

.spread-stage.is-cover-page .spread-page {
  justify-items: end;
  padding-right: 0.5%;
}

.page-stage.is-spread-page .pdf-canvas,
.spread-stage.is-spread-page .pdf-canvas {
  margin-left: auto;
  margin-right: auto;
}

.page-stage.is-spread-page,
.spread-stage.is-spread-page .spread-page {
  justify-items: center;
}

.page-stage.is-spread-page::before,
.page-stage.is-spread-page::after,
.spread-stage.is-spread-page::before,
.spread-stage.is-spread-page::after {
  opacity: 0.74;
}

.paper-shadow {
  display: none;
}

.pdf-canvas {
  display: block;
  max-width: 100%;
  max-height: 100%;
  margin: auto;
  background: #fff;
}

.page-stage .pdf-canvas {
  width: auto;
  height: auto;
  box-shadow: 0 10px 24px rgba(21, 18, 13, 0.18);
}

.turn-curl {
  --curl-x: 100%;
  --curl-opacity: 0;
  position: absolute;
  inset: 0;
  background:
    linear-gradient(105deg, transparent 0 66%, rgba(255, 255, 255, 0.68) 72%, rgba(21, 18, 13, 0.2) 76%, transparent 80%),
    linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.32), transparent);
  clip-path: polygon(var(--curl-x) 0, 100% 0, 100% 100%, calc(var(--curl-x) - 13%) 100%);
  opacity: var(--curl-opacity);
  pointer-events: none;
  transition: opacity 140ms ease;
  z-index: 4;
  display: none;
}

.is-curl-left .turn-curl {
  transform: scaleX(-1);
}

.loading-slab {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 5;
  background: rgba(246, 239, 224, 0.66);
  color: var(--teal);
  font-weight: 900;
  letter-spacing: 0;
}

.loading-slab.is-hidden {
  display: none;
}

.reader-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(5px, 0.9vmin, 9px);
  margin-top: clamp(5px, 0.9vmin, 9px);
}

.icon-button,
.text-button {
  min-width: clamp(24px, 3.6vmin, 36px);
  height: clamp(24px, 3.6vmin, 36px);
  border: 2px solid var(--ink);
  background: #fff8df;
  color: var(--ink);
  display: inline-grid;
  place-items: center;
  font-weight: 900;
  box-shadow: 3px 4px 0 var(--ink);
  cursor: pointer;
}

.icon-button {
  border-radius: 50%;
  font-size: clamp(18px, 3.2vmin, 28px);
  line-height: 1;
}

.icon-button:disabled,
.text-button:disabled {
  opacity: 0.42;
  cursor: not-allowed;
  box-shadow: none;
}

.icon-button:hover:not(:disabled),
.text-button:hover {
  background: var(--red);
  color: #fff8df;
}

.icon-button.is-zero {
  width: clamp(30px, 4.4vmin, 44px);
  height: clamp(30px, 4.4vmin, 44px);
  padding: 4px;
  border-radius: 12px;
  background: #101820;
}

.icon-button.is-zero img,
.chapter-zero img,
.voice-button img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.text-button {
  border-radius: 999px;
  padding: 0 clamp(8px, 1.5vmin, 14px);
  font-size: clamp(9px, 1.35vmin, 12px);
}

.zero-index {
  min-height: 0;
  height: 100%;
  border: 0;
  background: transparent;
  box-shadow: none;
  overflow: hidden;
}

.index-header {
  display: none;
}

.index-header p {
  margin: 0 0 4px;
  color: var(--teal);
  font-weight: 900;
  font-size: clamp(8px, 1.2vmin, 11px);
}

.index-header h1 {
  margin: 0;
  font-family: var(--archive-serif);
  font-size: clamp(22px, 5vmin, 44px);
  line-height: 0.92;
  letter-spacing: 0;
}

.zero-grid {
  position: absolute;
  inset: 0;
}

.home-question {
  position: absolute;
  left: 3%;
  right: 3%;
  bottom: clamp(6px, 1.4vmin, 16px);
  z-index: 2;
  margin: 0;
  color: rgba(21, 18, 13, 0.72);
  font-family: var(--archive-mono);
  font-size: clamp(8px, 1.15vmin, 12px);
  font-weight: 800;
  line-height: 1.1;
  text-align: center;
  letter-spacing: 0;
  text-shadow: 0 1px 0 rgba(255, 248, 223, 0.45);
  pointer-events: none;
}

.zero-card {
  position: absolute;
  left: calc(var(--x) * 1%);
  top: calc(var(--y) * 1%);
  width: clamp(72px, calc(var(--w) * 1.35vmin), 148px);
  aspect-ratio: 1;
  transform: translate(-50%, -50%) rotate(var(--r));
  border: 0;
  background: transparent;
  cursor: pointer;
  animation: zero-float 3.8s ease-in-out infinite;
  animation-delay: var(--delay);
}

.zero-card img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: drop-shadow(5px 7px 0 rgba(21, 18, 13, 0.75));
  transition: transform 170ms ease, filter 170ms ease;
}

.zero-card span {
  position: absolute;
  left: 50%;
  bottom: -7px;
  transform: translateX(-50%);
  min-width: 34px;
  padding: 2px 6px;
  background: var(--ink);
  color: #fff8df;
  font-size: clamp(9px, 1.25vmin, 12px);
  font-weight: 900;
}

.zero-card:hover img,
.zero-card.is-pressed img {
  transform: translate(2px, 3px) scale(0.96);
  filter: drop-shadow(1px 2px 0 rgba(21, 18, 13, 0.8));
}

@keyframes zero-float {
  0%,
  100% {
    margin-top: 0;
  }
  50% {
    margin-top: -10px;
  }
}

.chapter-reader {
  margin-left: 0;
  position: relative;
  display: block;
}

.chapter-reader .reader-topline {
  position: relative;
  z-index: 13;
}

.chapter-head {
  position: absolute;
  left: clamp(38px, 4.1vmin, 62px);
  right: clamp(94px, 10.5vmin, 128px);
  top: clamp(42px, 5.6vmin, 54px);
  z-index: 12;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: clamp(8px, 1.8vmin, 16px);
  align-items: end;
  padding: 0;
  border-bottom: 0;
  pointer-events: none;
}

.chapter-number {
  margin: 0 0 2px;
  color: var(--red);
  font-family: var(--archive-mono);
  font-size: clamp(8px, 1.2vmin, 11px);
  font-weight: 900;
}

.chapter-head h1 {
  max-width: min(760px, 72vw);
  margin: 0;
  font-family: var(--archive-serif);
  font-size: clamp(13px, 2.05vmin, 20px);
  line-height: 1;
  letter-spacing: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chapter-head p:not(.chapter-number) {
  display: none;
}

.chapter-zero {
  position: absolute;
  right: clamp(10px, 1.6vmin, 18px);
  top: clamp(42px, 5.8vmin, 56px);
  z-index: 14;
  width: clamp(44px, 7vmin, 72px);
  aspect-ratio: 1;
  padding: 5px;
  border: 2px solid var(--ink);
  border-radius: 14px;
  background: #101820;
  box-shadow: 4px 5px 0 var(--ink);
  cursor: pointer;
  display: none;
}

.bound-book-panel {
  position: absolute;
  inset: 0;
  min-height: 0;
  padding: 0;
  display: block;
}

.bound-book-panel .book-meta {
  position: absolute;
  left: clamp(38px, 4.1vmin, 62px);
  right: clamp(260px, 26vw, 420px);
  top: clamp(86px, 10.6vmin, 100px);
  z-index: 12;
  margin-left: 0;
  margin-right: 0;
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid rgba(21, 18, 13, 0.38);
  padding-top: clamp(4px, 0.8vmin, 7px);
  background: rgba(246, 239, 224, 0.48);
}

.spread-stage {
  position: absolute;
  left: calc(50% - clamp(104px, 12vw, 230px));
  right: auto;
  top: clamp(106px, 13vmin, 120px);
  bottom: clamp(24px, 3.2vmin, 34px);
  aspect-ratio: var(--page-ratio, 1.56);
  width: auto;
  max-width: calc(100% - clamp(310px, 27vw, 470px));
  min-height: 0;
  height: auto;
  align-self: stretch;
  margin-top: 0;
  transform: translateX(-50%);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: stretch;
  background: transparent;
  border: 0;
  box-shadow: none;
  perspective: 1600px;
}

.spread-page {
  position: relative;
  min-width: 0;
  display: grid;
  place-items: center;
  padding: 0;
  background: transparent;
}

.spread-page:first-of-type {
  box-shadow: none;
}

.spread-page:last-of-type {
  box-shadow: none;
}

.spread-page .pdf-canvas {
  width: auto;
  height: auto;
  box-shadow: 0 12px 28px rgba(21, 18, 13, 0.11);
}

.gutter {
  display: none;
}

.page-ghost {
  position: absolute;
  z-index: 6;
  pointer-events: none;
  object-fit: fill;
  transform: translate3d(0, 0, 0) rotateY(0deg);
  transform-origin: right center;
  opacity: 1;
  box-shadow: 0 14px 32px rgba(21, 18, 13, 0.22);
  transition:
    transform 620ms cubic-bezier(0.2, 0.72, 0.18, 1),
    opacity 620ms cubic-bezier(0.2, 0.72, 0.18, 1),
    filter 620ms cubic-bezier(0.2, 0.72, 0.18, 1);
  will-change: transform, opacity, filter;
}

.bound-book-panel .reader-controls {
  position: absolute;
  left: calc(50% - clamp(104px, 12vw, 230px));
  bottom: clamp(4px, 0.8vmin, 8px);
  z-index: 15;
  transform: translateX(-50%);
  margin: 0;
}

.voice-button-field {
  position: absolute;
  right: clamp(76px, 6.2vw, 132px);
  top: 50%;
  z-index: 16;
  width: clamp(168px, 16.2vw, 252px);
  height: clamp(246px, 37vmin, 420px);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-template-rows: repeat(4, minmax(0, 1fr));
  gap: clamp(8px, 1.3vmin, 16px);
  align-items: center;
  justify-items: center;
  pointer-events: none;
  transform: translateY(-43%);
}

.voice-button-field::after {
  content: "Switch to human service? Please press 0";
  position: absolute;
  left: 50%;
  top: calc(100% + clamp(10px, 1.4vmin, 18px));
  width: max-content;
  max-width: 120%;
  transform: translateX(-50%);
  color: var(--ink);
  font-family: var(--archive-mono);
  font-size: clamp(7px, 1.05vmin, 10px);
  font-weight: 800;
  letter-spacing: 0;
  line-height: 1.1;
  text-align: center;
  text-transform: uppercase;
  text-shadow: 0.5px 0 rgba(21, 18, 13, 0.24);
  pointer-events: none;
}

.voice-button {
  position: relative;
  grid-column: var(--col);
  grid-row: var(--row);
  width: clamp(48px, calc(var(--s) * 1vmin), 84px);
  aspect-ratio: 1;
  padding: clamp(4px, 0.6vmin, 7px);
  border: 2px solid var(--ink);
  border-radius: clamp(12px, 1.6vmin, 18px);
  background: #101820;
  box-shadow:
    4px 5px 0 var(--ink),
    0 12px 22px rgba(21, 18, 13, 0.2);
  cursor: pointer;
  pointer-events: auto;
  transform: rotate(var(--r));
  transition: transform 150ms ease, filter 150ms ease, background 150ms ease;
  animation: voice-button-float 4.4s ease-in-out infinite;
  animation-delay: var(--delay);
}

.voice-button:hover,
.voice-button.is-playing {
  background: var(--red);
  filter: saturate(1.08);
}

.voice-button:active,
.voice-button.is-playing {
  transform: translate(2px, 3px) rotate(var(--r)) scale(0.94);
  box-shadow:
    1px 2px 0 var(--ink),
    0 8px 16px rgba(21, 18, 13, 0.18);
}

.voice-button.is-error {
  background: var(--teal);
}

@keyframes voice-button-float {
  0%,
  100% {
    margin-top: 0;
  }
  50% {
    margin-top: -6px;
  }
}

.page-ghost.is-next {
  opacity: 0;
  filter: blur(1.2px);
  transform: translate3d(-9%, 0, 0) rotateY(-18deg) scale(0.985);
}

.page-ghost.is-prev {
  opacity: 0;
  filter: blur(1.2px);
  transform: translate3d(9%, 0, 0) rotateY(18deg) scale(0.985);
  transform-origin: left center;
}

.turn-layer {
  --turn-progress: 0;
  --turn-rotate: 0deg;
  --turn-lift: 0px;
  --turn-skew: 0deg;
  --turn-tilt: 0deg;
  --turn-curl: 0%;
  --turn-shadow: 0.2;
  --turn-shine: 0;
  position: absolute;
  z-index: 22;
  pointer-events: none;
  perspective: 1900px;
  transform-style: preserve-3d;
  transition: opacity 240ms ease;
}

.turn-layer.is-clearing {
  opacity: 0;
}

.turn-target,
.turn-sheet,
.turn-target-half,
.turn-strips,
.turn-strip,
.turn-sheet-shade {
  position: absolute;
}

.turn-target {
  inset: 0;
  z-index: 1;
  overflow: hidden;
  background:
    linear-gradient(90deg, rgba(21, 18, 13, 0.06), transparent 9%, transparent 91%, rgba(21, 18, 13, 0.05)),
    #fffaf0;
  filter: saturate(0.98) contrast(1.01);
}

.turn-target::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(50% - 1px);
  width: 2px;
  z-index: 2;
  background:
    linear-gradient(90deg, rgba(21, 18, 13, 0.18), rgba(255, 255, 255, 0.56), rgba(21, 18, 13, 0.1));
  opacity: 0.54;
}

.turn-target-half {
  top: 0;
  bottom: 0;
  width: 50%;
  height: 100%;
  object-fit: fill;
}

.turn-target-half.is-left {
  left: 0;
}

.turn-target-half.is-right {
  right: 0;
}

.turn-target.is-cover-target .turn-target-half.is-left:where([src=""]) {
  display: none;
}

.turn-target.is-cover-target .turn-target-half.is-right {
  left: 50%;
  right: auto;
  width: 50%;
}

.turn-sheet {
  top: 0;
  bottom: 0;
  height: 100%;
  z-index: 2;
  transform-style: preserve-3d;
  transform:
    translateZ(var(--turn-lift))
    rotateY(var(--turn-rotate))
    rotateZ(var(--turn-tilt))
    skewY(var(--turn-skew));
  will-change: transform;
  background: #fff;
  border-radius: 2px;
  clip-path: polygon(0 0, 100% var(--turn-curl), 100% calc(100% - var(--turn-curl)), 0 100%);
  filter: drop-shadow(calc(var(--turn-shadow) * -22px) 12px 18px rgba(21, 18, 13, 0.26));
}

.turn-layer.is-prev .turn-sheet {
  filter: drop-shadow(calc(var(--turn-shadow) * 22px) 12px 18px rgba(21, 18, 13, 0.26));
  clip-path: polygon(0 var(--turn-curl), 100% 0, 100% 100%, 0 calc(100% - var(--turn-curl)));
}

.turn-strips {
  inset: 0;
  z-index: 2;
  overflow: visible;
  transform-style: preserve-3d;
}

.turn-strip {
  top: 0;
  bottom: 0;
  background-color: #fff;
  background-repeat: no-repeat;
  backface-visibility: hidden;
  transform-style: preserve-3d;
  will-change: transform, filter;
  box-shadow: none;
}

.turn-strip::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.12), transparent 46%, rgba(21, 18, 13, 0.035));
  opacity: calc(var(--turn-shadow) * 0.16);
  pointer-events: none;
}

.turn-sheet.is-back-phase .turn-strip::after {
  background:
    linear-gradient(90deg, rgba(21, 18, 13, 0.035), transparent 46%, rgba(255, 255, 255, 0.12));
}

.turn-sheet::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  width: clamp(2px, 0.5vmin, 7px);
  z-index: 5;
  background:
    linear-gradient(90deg, rgba(21, 18, 13, 0.32), rgba(255, 255, 255, 0.58), rgba(21, 18, 13, 0.14));
  opacity: calc(0.24 + var(--turn-shadow) * 0.55);
  pointer-events: none;
}

.turn-layer.is-next .turn-sheet::before {
  left: -1px;
}

.turn-layer.is-prev .turn-sheet::before {
  right: -1px;
  transform: scaleX(-1);
}

.turn-sheet::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 4;
  pointer-events: none;
  background:
    linear-gradient(90deg, transparent 0 62%, rgba(255, 255, 255, calc(var(--turn-shine) * 0.58)) 75%, rgba(21, 18, 13, calc(var(--turn-shadow) * 0.2)) 100%),
    radial-gradient(ellipse at 78% 50%, rgba(255, 255, 255, calc(var(--turn-shine) * 0.46)), transparent 56%);
  opacity: calc(0.28 + var(--turn-progress) * 0.34);
}

.turn-layer.is-prev .turn-sheet::after {
  transform: scaleX(-1);
}

.turn-sheet-shade {
  inset: 0;
  z-index: 3;
  background:
    linear-gradient(90deg, rgba(21, 18, 13, calc(var(--turn-shadow) * 0.38)), transparent 23%, rgba(255, 255, 255, var(--turn-shine)) 52%, transparent 76%),
    radial-gradient(ellipse at 50% 50%, rgba(255, 255, 255, calc(var(--turn-shine) * 0.4)), transparent 64%);
  mix-blend-mode: multiply;
  opacity: calc(0.24 + var(--turn-progress) * 0.42);
  backface-visibility: hidden;
  pointer-events: none;
}

.turn-layer.is-next .turn-sheet {
  transform-origin: left center;
}

.turn-layer.is-prev .turn-sheet {
  transform-origin: right center;
}

.turn-layer.is-cover-turn .turn-sheet {
  transform-origin: left center;
}

@media (max-width: 980px) {
  .reader-topline {
    align-items: center;
    flex-direction: row;
  }

  .book-layout {
    grid-template-columns: minmax(0, 0.34fr) minmax(0, 0.66fr);
    gap: 6px;
  }

  .book-panel,
  .zero-index {
    min-height: 0;
  }

  .zero-card {
    width: clamp(46px, calc(var(--w) * 1.08vmin), 96px);
  }

  .chapter-head {
    grid-template-columns: 1fr auto;
  }

  .spread-stage {
    min-height: 0;
    height: auto;
    grid-template-columns: 1fr;
    left: calc(50% - 86px);
    max-width: calc(100% - 210px);
  }

  .bound-book-panel .book-meta {
    right: 190px;
  }

  .bound-book-panel .reader-controls {
    left: calc(50% - 86px);
  }

  .voice-button-field {
    right: 48px;
    width: 148px;
    height: 224px;
    gap: 8px;
  }

  .voice-button-field::after {
    max-width: 140%;
    font-size: 8px;
  }

  .voice-button {
    width: clamp(38px, 5.8vmin, 58px);
  }
}