:root {
  color-scheme: light;
  --bg: #f4f1ea;
  --surface: #ffffff;
  --surface-2: #f7f7f4;
  --ink: #171717;
  --muted: #626262;
  --line: #d9d6ce;
  --accent: #0f766e;
  --accent-dark: #0b5751;
  --danger: #a32929;
  --shadow: 0 20px 60px rgba(28, 25, 20, 0.18);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.64), rgba(244, 241, 234, 0.86)),
    var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
input,
textarea {
  font: inherit;
}

button,
.ghost-button {
  min-height: 42px;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #ffffff;
  padding: 0 16px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  white-space: nowrap;
}

button:hover,
.ghost-button:hover {
  background: var(--accent-dark);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.ghost-button {
  border: 1px solid var(--line);
  background: #ffffff;
  color: var(--ink);
}

.ghost-button:hover {
  background: var(--surface-2);
}

.danger-button {
  background: #ffffff;
  border: 1px solid rgba(163, 41, 41, 0.35);
  color: var(--danger);
}

.danger-button:hover {
  background: #fff2f2;
}

.hidden {
  display: none !important;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.admin-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 40px 0;
}

.admin-header,
.viewer-header,
.panel-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

h1,
h2 {
  margin: 0;
  letter-spacing: 0;
}

h1 {
  font-size: clamp(2rem, 4vw, 4.2rem);
  line-height: 0.95;
}

h2 {
  font-size: 1.15rem;
}

.panel {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 12px 28px rgba(28, 25, 20, 0.08);
  padding: 22px;
}

.stack-form,
.upload-form,
.result-grid {
  display: grid;
  gap: 16px;
}

label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
}

input,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #ffffff;
  color: var(--ink);
  padding: 12px;
  resize: vertical;
}

.inline-form,
.copy-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: start;
}

.field-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 0.7fr);
  gap: 16px;
}

.form-message {
  min-height: 22px;
  margin: 0;
  color: var(--muted);
}

.document-list {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.document-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  padding: 14px;
}

.document-item.is-disabled {
  opacity: 0.56;
}

.document-meta {
  display: grid;
  gap: 4px;
  min-width: 0;
}

.document-meta strong {
  overflow-wrap: anywhere;
}

.document-meta span,
.empty-state {
  color: var(--muted);
}

.document-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.viewer-page {
  overflow-x: hidden;
  background:
    radial-gradient(circle at 50% 0%, rgba(255, 255, 255, 0.08), transparent 34rem),
    #262421;
}

.viewer-shell {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  gap: 14px;
  padding: 22px;
}

.viewer-header h1 {
  max-width: min(820px, 72vw);
  font-size: clamp(1.35rem, 2.5vw, 2.7rem);
  line-height: 1.05;
  overflow-wrap: anywhere;
}

.viewer-page .viewer-header h1 {
  color: #ffffff;
}

.viewer-page .viewer-header .eyebrow,
.viewer-page .zoom-control {
  color: rgba(255, 255, 255, 0.82);
}

.book-stage {
  position: relative;
  min-height: 0;
  display: grid;
  align-items: center;
  justify-items: center;
  perspective: 2600px;
  overflow: hidden;
}

.book {
  position: relative;
  width: min(100%, var(--book-width, 100%));
  height: var(--book-height, 380px);
  min-height: 380px;
  display: grid;
  align-items: center;
  justify-items: center;
  contain: layout;
  isolation: isolate;
}

.flip-root {
  position: relative;
  width: 100%;
  height: 100%;
}

.flip-root.stf__parent {
  margin: 0 auto;
  min-height: 0 !important;
  min-width: 0 !important;
}

.flip-root .stf__wrapper {
  position: relative;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
}

.flip-root .stf__block {
  border-radius: 8px;
  overflow: visible;
}

.flipbook-page,
.flip-root .stf__item {
  border-radius: 8px;
  background: #ffffff;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.24);
  overflow: hidden;
}

.flipbook-page {
  width: 100%;
  height: 100%;
}

.flipbook-page canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.flip-root .stf__item::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.12), transparent 7%, transparent 93%, rgba(0, 0, 0, 0.1)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.16), transparent 22%, transparent 80%, rgba(0, 0, 0, 0.05));
  opacity: 0.22;
  mix-blend-mode: multiply;
}

.loading-state {
  color: var(--muted);
  font-weight: 700;
}

.spread {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: nowrap;
  gap: var(--spread-gap, 24px);
  width: min(100%, var(--spread-width, 100%));
  height: min(100%, var(--spread-height, 100%));
  transform-origin: center;
  will-change: transform;
}

.page-shell {
  position: relative;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #ffffff;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.22);
  overflow: hidden;
  transform: translateZ(0);
}

.page-shell::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.11), transparent 6%, transparent 94%, rgba(0, 0, 0, 0.1)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.14), transparent 22%, transparent 80%, rgba(0, 0, 0, 0.05));
  opacity: 0.24;
  mix-blend-mode: multiply;
}

.page-shell canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

.spread-after-flip {
  animation: spreadAfterFlip 280ms ease-out both;
}

.flip-layer {
  position: absolute;
  z-index: 5;
  pointer-events: none;
  transform-style: preserve-3d;
  backface-visibility: visible;
  overflow: visible;
  will-change: transform, opacity, filter;
}

.flip-sheet {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  overflow: visible;
  will-change: transform;
}

.flip-bend {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
  will-change: transform, clip-path, border-radius;
}

.flip-face {
  position: absolute;
  inset: 0;
  overflow: hidden;
  border-radius: 8px;
  backface-visibility: hidden;
  transform-style: preserve-3d;
  background: #ffffff;
}

.flip-face-front {
  transform: translateZ(0.8px);
}

.flip-face-back {
  transform: rotateY(180deg) translateZ(0.8px);
}

.flip-face .page-shell {
  width: 100%;
  height: 100%;
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.28);
}

.flip-layer.is-turning {
  animation-duration: 820ms;
  animation-timing-function: cubic-bezier(0.18, 0.78, 0.16, 1);
  animation-fill-mode: both;
}

.flip-layer.flip-next.is-turning {
  animation-name: pageFlipNext;
}

.flip-layer.flip-prev.is-turning {
  animation-name: pageFlipPrev;
}

.flip-layer::before,
.flip-layer::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  border-radius: 6px;
}

.flip-layer::before {
  background:
    radial-gradient(80% 68% at 0% 100%, rgba(255, 255, 255, 0.48), transparent 42%),
    linear-gradient(104deg, transparent 0 46%, rgba(255, 255, 255, 0.36) 55%, transparent 68%),
    linear-gradient(90deg, rgba(0, 0, 0, 0.24), transparent 18%, transparent 74%, rgba(255, 255, 255, 0.24));
  opacity: 0;
}

.flip-layer::after {
  background:
    radial-gradient(70% 72% at 0% 100%, rgba(0, 0, 0, 0.34), transparent 46%),
    linear-gradient(90deg, rgba(0, 0, 0, 0.28), transparent 34%, rgba(255, 255, 255, 0.16));
  opacity: 0;
}

.flip-layer.is-cover-turn.flip-next.is-turning {
  animation-name: coverFlipNext;
}

.flip-layer.is-cover-turn.flip-prev.is-turning {
  animation-name: coverFlipPrev;
}

.flip-next {
  transform-origin: left bottom;
}

.flip-prev {
  transform-origin: right bottom;
}

.flip-next.is-turning::before,
.flip-prev.is-turning::before {
  animation: flipCurlLight 820ms ease-in-out both;
}

.flip-next.is-turning::after,
.flip-prev.is-turning::after {
  animation: flipCurlShadow 820ms ease-in-out both;
}

.flip-next.is-turning .flip-sheet {
  animation: pageSheetNext 820ms cubic-bezier(0.18, 0.78, 0.16, 1) both;
}

.flip-prev.is-turning .flip-sheet {
  animation: pageSheetPrev 820ms cubic-bezier(0.18, 0.78, 0.16, 1) both;
}

.flip-next.is-turning .flip-bend {
  transform-origin: left bottom;
  animation: pageBendNext 820ms cubic-bezier(0.18, 0.78, 0.16, 1) both;
}

.flip-prev.is-turning .flip-bend {
  transform-origin: right bottom;
  animation: pageBendPrev 820ms cubic-bezier(0.18, 0.78, 0.16, 1) both;
}

.viewer-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 8px 0 2px;
}

.page-status {
  min-width: 110px;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.82);
  display: grid;
  place-items: center;
  font-weight: 800;
}

.zoom-control {
  width: 190px;
  grid-auto-flow: column;
  align-items: center;
  gap: 10px;
  color: var(--ink);
}

.zoom-control input {
  padding: 0;
}

.nav-hit {
  position: absolute;
  z-index: 3;
  top: 50%;
  width: 48px;
  height: 72px;
  min-height: 72px;
  padding: 0;
  transform: translateY(-50%);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--line);
  color: var(--ink);
  font-size: 2.2rem;
}

.nav-hit:hover {
  background: #ffffff;
}

.nav-hit-left {
  left: 8px;
}

.nav-hit-right {
  right: 8px;
}

.embed-mode {
  background: transparent;
}

.embed-mode .viewer-shell {
  min-height: 100vh;
  padding: 10px;
  grid-template-rows: minmax(0, 1fr) auto;
}

.embed-mode .viewer-controls {
  flex-wrap: wrap;
}

.embed-mode .book {
  min-height: 300px;
}

@keyframes pageFlipNext {
  from {
    transform: translate3d(0, 0, 0) rotateY(0deg) rotateZ(0deg);
    opacity: 1;
    filter: drop-shadow(0 12px 18px rgba(0, 0, 0, 0.18));
  }
  26% {
    transform: translate3d(-10px, 3px, 24px) rotateY(-42deg) rotateZ(-1.4deg);
    opacity: 1;
    filter: drop-shadow(-16px 18px 24px rgba(0, 0, 0, 0.26));
  }
  58% {
    transform: translate3d(-18px, 7px, 36px) rotateY(-112deg) rotateZ(-2.2deg);
    opacity: 1;
    filter: drop-shadow(-24px 22px 32px rgba(0, 0, 0, 0.34));
  }
  100% {
    transform: translate3d(-26px, 4px, 8px) rotateY(-178deg) rotateZ(-0.4deg);
    opacity: 0;
    filter: drop-shadow(-12px 12px 22px rgba(0, 0, 0, 0));
  }
}

@keyframes pageFlipPrev {
  from {
    transform: translate3d(0, 0, 0) rotateY(0deg) rotateZ(0deg);
    opacity: 1;
    filter: drop-shadow(0 12px 18px rgba(0, 0, 0, 0.18));
  }
  26% {
    transform: translate3d(10px, 3px, 24px) rotateY(42deg) rotateZ(1.4deg);
    opacity: 1;
    filter: drop-shadow(16px 18px 24px rgba(0, 0, 0, 0.26));
  }
  58% {
    transform: translate3d(18px, 7px, 36px) rotateY(112deg) rotateZ(2.2deg);
    opacity: 1;
    filter: drop-shadow(24px 22px 32px rgba(0, 0, 0, 0.34));
  }
  100% {
    transform: translate3d(26px, 4px, 8px) rotateY(178deg) rotateZ(0.4deg);
    opacity: 0;
    filter: drop-shadow(12px 12px 22px rgba(0, 0, 0, 0));
  }
}

@keyframes coverFlipNext {
  from {
    transform: translate3d(0, 0, 0) rotateY(0deg) rotateZ(0deg);
    opacity: 1;
    filter: drop-shadow(0 12px 18px rgba(0, 0, 0, 0.18));
  }
  24% {
    transform: translate3d(-10px, 3px, 24px) rotateY(-40deg) rotateZ(-1.2deg);
    opacity: 1;
    filter: drop-shadow(-16px 18px 24px rgba(0, 0, 0, 0.26));
  }
  58% {
    transform: translate3d(-20px, 7px, 36px) rotateY(-112deg) rotateZ(-2deg);
    opacity: 1;
    filter: drop-shadow(-24px 22px 32px rgba(0, 0, 0, 0.34));
  }
  100% {
    transform: translate3d(-30px, 5px, 8px) rotateY(-178deg) rotateZ(-0.4deg);
    opacity: 0;
    filter: drop-shadow(-12px 12px 22px rgba(0, 0, 0, 0));
  }
}

@keyframes coverFlipPrev {
  from {
    transform: translate3d(0, 0, 0) rotateY(0deg) rotateZ(0deg);
    opacity: 1;
    filter: drop-shadow(0 12px 18px rgba(0, 0, 0, 0.18));
  }
  24% {
    transform: translate3d(10px, 3px, 24px) rotateY(40deg) rotateZ(1.2deg);
    opacity: 1;
    filter: drop-shadow(16px 18px 24px rgba(0, 0, 0, 0.26));
  }
  58% {
    transform: translate3d(20px, 7px, 36px) rotateY(112deg) rotateZ(2deg);
    opacity: 1;
    filter: drop-shadow(24px 22px 32px rgba(0, 0, 0, 0.34));
  }
  100% {
    transform: translate3d(30px, 5px, 8px) rotateY(178deg) rotateZ(0.4deg);
    opacity: 0;
    filter: drop-shadow(12px 12px 22px rgba(0, 0, 0, 0));
  }
}

@keyframes pageSheetNext {
  0% {
    transform: skewY(0deg) scaleX(1);
  }
  30% {
    transform: skewY(-1.2deg) scaleX(0.985);
  }
  58% {
    transform: skewY(-2.6deg) scaleX(0.955);
  }
  100% {
    transform: skewY(-0.4deg) scaleX(0.99);
  }
}

@keyframes pageSheetPrev {
  0% {
    transform: skewY(0deg) scaleX(1);
  }
  30% {
    transform: skewY(1.2deg) scaleX(0.985);
  }
  58% {
    transform: skewY(2.6deg) scaleX(0.955);
  }
  100% {
    transform: skewY(0.4deg) scaleX(0.99);
  }
}

@keyframes pageBendNext {
  0% {
    border-radius: 8px;
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    transform: perspective(900px) rotateX(0deg) skewY(0deg);
  }
  32% {
    border-radius: 8px 16px 22px 8px;
    clip-path: polygon(0 0, 99% 2%, 96% 96%, 0 100%);
    transform: perspective(900px) rotateX(2.6deg) skewY(-1.8deg);
  }
  58% {
    border-radius: 8px 24px 34px 8px;
    clip-path: polygon(0 0, 95% 5%, 86% 92%, 0 100%);
    transform: perspective(900px) rotateX(5.6deg) skewY(-3.4deg);
  }
  100% {
    border-radius: 8px 14px 18px 8px;
    clip-path: polygon(0 0, 100% 0, 98% 100%, 0 100%);
    transform: perspective(900px) rotateX(1deg) skewY(-0.6deg);
  }
}

@keyframes pageBendPrev {
  0% {
    border-radius: 8px;
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    transform: perspective(900px) rotateX(0deg) skewY(0deg);
  }
  32% {
    border-radius: 16px 8px 8px 22px;
    clip-path: polygon(1% 2%, 100% 0, 100% 100%, 4% 96%);
    transform: perspective(900px) rotateX(2.6deg) skewY(1.8deg);
  }
  58% {
    border-radius: 24px 8px 8px 34px;
    clip-path: polygon(5% 5%, 100% 0, 100% 100%, 14% 92%);
    transform: perspective(900px) rotateX(5.6deg) skewY(3.4deg);
  }
  100% {
    border-radius: 14px 8px 8px 18px;
    clip-path: polygon(0 0, 100% 0, 100% 100%, 2% 100%);
    transform: perspective(900px) rotateX(1deg) skewY(0.6deg);
  }
}

@keyframes flipCurlLight {
  0% {
    opacity: 0.04;
  }
  28% {
    opacity: 0.36;
  }
  58% {
    opacity: 0.52;
  }
  100% {
    opacity: 0;
  }
}

@keyframes flipCurlShadow {
  0% {
    opacity: 0;
  }
  30% {
    opacity: 0.28;
  }
  58% {
    opacity: 0.46;
  }
  100% {
    opacity: 0;
  }
}

@keyframes spreadAfterFlip {
  from {
    opacity: 0.88;
    transform: translateX(0) scale(0.998);
  }
  to {
    opacity: 1;
    transform: translateX(0) scale(1);
  }
}

@media (max-width: 760px) {
  .admin-shell {
    width: min(100% - 20px, 1120px);
    padding: 20px 0;
  }

  .admin-header,
  .viewer-header,
  .panel-title-row,
  .document-item {
    align-items: stretch;
    grid-template-columns: 1fr;
    flex-direction: column;
  }

  .field-grid,
  .inline-form,
  .copy-row {
    grid-template-columns: 1fr;
  }

  .document-actions {
    justify-content: flex-start;
  }

  .viewer-shell {
    padding: 10px;
  }

  .viewer-header h1 {
    max-width: 100%;
  }

  .viewer-controls {
    flex-wrap: wrap;
  }

  .zoom-control {
    width: min(100%, 260px);
  }

  .nav-hit {
    width: 40px;
    height: 58px;
    min-height: 58px;
  }

  .spread {
    gap: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .spread-after-flip,
  .flip-layer,
  .flip-layer::before,
  .flip-layer::after,
  .flip-sheet,
  .flip-bend,
  .flip-face,
  .flip-face .page-shell {
    animation: none !important;
    transition: none !important;
  }

  .flip-layer,
  .flip-sheet,
  .flip-bend,
  .flip-face {
    transform: none !important;
  }

  .page-shell::after {
    opacity: 0.18;
  }
}