:root {
  --bg-deep: #4a1822;
  --bg-warm: #8c4451;
  --bg-gold: #d2b08d;
  --paper: #fbf4e6;
  --paper-shadow: #efe3cd;
  --ink: #5d292c;
  --ink-soft: #8b685d;
  --accent: #7a2c35;
  --accent-soft: rgba(122, 44, 53, 0.1);
  --line: rgba(93, 41, 44, 0.14);
  --stage-padding: clamp(0.75rem, 1.5vw, 1.5rem);
  --arrow-clearance: clamp(48px, 10vw, 140px);
  --frame-safe-width: calc(
    100vw - (var(--stage-padding) * 2) - var(--arrow-clearance)
  );
  --spread-width: min(1700px, var(--frame-safe-width));
  --single-width: min(1360px, var(--frame-safe-width));
  --width: var(--spread-width);
  --height: min(900px, calc(100vh - 8rem));
  --page-padding: clamp(1rem, 2vw, 2.25rem);
  --content-scale: 1;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow: hidden;
  font-family: system-ui, -apple-system, "Segoe UI", Tahoma, Arial, sans-serif;
  color: var(--paper);
  background: #1a1a1a;
}

body.single-page-view {
  --width: var(--single-width);
}

.experience {
  width: 100%;
  height: 100vh;
  padding: var(--stage-padding);
  display: grid;
  grid-template-rows: minmax(0, 1fr) auto;
  gap: clamp(0.75rem, 1.5vw, 1.25rem);
}

.viewer-toolbar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.75rem;
  width: max-content;
  max-width: 100%;
  margin: 0 auto;
  padding: 0.5rem;
  border-radius: 999px;
  background: rgba(251, 244, 230, 0.08);
  box-shadow:
    inset 0 0 0 1px rgba(251, 244, 230, 0.1),
    0 18px 36px rgba(45, 16, 24, 0.18);
  backdrop-filter: blur(18px);
}

.display-toggle {
  border: 0;
  border-radius: 999px;
  width: 3.2rem;
  height: 3.2rem;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--paper);
  background: rgba(251, 244, 230, 0.1);
  box-shadow: inset 0 0 0 1px rgba(251, 244, 230, 0.14);
  cursor: pointer;
  transition: background-color 160ms ease, transform 160ms ease;
}

.display-toggle:hover {
  background: rgba(251, 244, 230, 0.18);
  transform: translateY(-1px);
}

.display-toggle:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.layout-icon {
  display: none;
  width: 1.45rem;
  height: 1.45rem;
}

.layout-icon svg,
.zoom-button svg,
.status-icon svg,
.nav-arrow svg {
  width: 100%;
  height: 100%;
  display: block;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.display-toggle[data-view="single"] .layout-icon-single,
.display-toggle[data-view="spread"] .layout-icon-spread {
  display: block;
}

.zoom-controls {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.25rem;
  border-radius: 999px;
  background: rgba(251, 244, 230, 0.08);
  box-shadow: inset 0 0 0 1px rgba(251, 244, 230, 0.12);
}

.zoom-button {
  width: 2.6rem;
  height: 2.6rem;
  border: 0;
  border-radius: 999px;
  background: rgba(251, 244, 230, 0.08);
  color: var(--paper);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 160ms ease, opacity 160ms ease;
}

.zoom-button:hover:not(:disabled) {
  background: rgba(251, 244, 230, 0.16);
}

.zoom-button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.zoom-value {
  min-width: 3.6rem;
  padding: 0 0.3rem;
  text-align: center;
  color: rgba(251, 244, 230, 0.92);
  font-size: 0.88rem;
}

.spread-status {
  min-width: 7rem;
  height: 3.2rem;
  padding: 0 1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  border-radius: 999px;
  background: rgba(251, 244, 230, 0.1);
  box-shadow: inset 0 0 0 1px rgba(251, 244, 230, 0.14);
  color: rgba(251, 244, 230, 0.94);
  font-size: 0.95rem;
}

.status-icon {
  width: 1.2rem;
  height: 1.2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.spread-status-value {
  line-height: 1;
  white-space: nowrap;
}

.book-stage {
  min-height: 0;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.book-frame {
  width: 100%;
  min-width: 0;
  max-width: calc(100% - var(--arrow-clearance));
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.book-container {
  width: var(--width);
  height: var(--height);
  position: relative;
  overflow: hidden;
  isolation: isolate;
  cursor: grab;
  touch-action: none;
  background: transparent;
}

body.compact-viewport .book-container {
  touch-action: pan-y;
}

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

.book-container:active {
  cursor: grabbing;
}

.page {
  width: calc(var(--width) / 2);
  height: var(--height);
  position: absolute;
  top: 0;
  padding: var(--page-padding);
  background:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.5), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
  user-select: none;
  overflow: hidden;
  backface-visibility: hidden;
  transform: translateZ(0);
}

.page::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(transparent 96%, rgba(93, 41, 44, 0.045) 100%),
    radial-gradient(circle at 15% 20%, rgba(122, 44, 53, 0.05), transparent 18%),
    radial-gradient(circle at 82% 75%, rgba(122, 44, 53, 0.03), transparent 14%);
  background-size: 100% 18px, auto, auto;
  opacity: 0.6;
  pointer-events: none;
}

#left-front,
#left-under {
  left: 0;
  background-image:
    linear-gradient(to left, rgba(122, 44, 53, 0.12) 0%, rgba(0, 0, 0, 0) 8%),
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.5), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
}

#right-front,
#right-under {
  left: 50%;
  background-image:
    linear-gradient(to right, rgba(122, 44, 53, 0.12) 0%, rgba(0, 0, 0, 0) 8%),
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.5), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
  border-left: 1px solid rgba(122, 44, 53, 0.14);
}

.front-page {
  z-index: 2;
}

.flap {
  width: var(--width);
  height: var(--height);
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  display: none;
  backface-visibility: hidden;
  transform: translateZ(0);
}

.flap-content {
  width: calc(var(--width) / 2);
  height: var(--height);
  position: absolute;
  top: 0;
  left: 0;
  padding: var(--page-padding);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.45), transparent 16%),
    linear-gradient(180deg, #f8f0dd 0%, #ecdec0 100%);
  box-sizing: border-box;
  overflow: hidden;
  backface-visibility: hidden;
  transform: translateZ(0);
  box-shadow: 0 18px 28px rgba(45, 16, 24, 0.2);
}

.fold-gradient {
  position: absolute;
  width: calc(var(--width) * 3);
  height: calc(var(--width) * 3);
  left: calc(var(--width) * -1.5);
  top: calc(var(--width) * -1.5);
  background: linear-gradient(
    to right,
    transparent 49.5%,
    rgba(0, 0, 0, 0.34) 50%,
    rgba(255, 255, 255, 0.7) 51.5%,
    rgba(0, 0, 0, 0.06) 58%,
    transparent 65%
  );
  opacity: 0;
  backface-visibility: hidden;
  transform: translateZ(0);
}

.book-container.is-turning .page,
.book-container.is-turning .flap,
.book-container.is-turning .flap-content,
.book-container.is-turning .fold-gradient {
  will-change: transform, clip-path, opacity;
}

.book-container.is-compact-turning #right-front,
.book-container.is-compact-turning #right-under {
  will-change: transform, opacity;
}

body.single-page-view .book-container::before,
.book-container--single-surface::before {
  opacity: 0;
}

body.single-page-view .book-container,
.book-container--single-surface {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), transparent 16%),
    linear-gradient(180deg, #fbf4e6 0%, #efdfc2 100%);
  box-shadow:
    0 30px 60px rgba(45, 16, 24, 0.22),
    inset 0 0 0 1px rgba(122, 44, 53, 0.1);
}

body.single-page-view #left-front,
body.single-page-view #left-under {
  display: none !important;
}

body.single-page-view #right-front,
body.single-page-view #right-under {
  left: 0;
  width: 100%;
  border-left: 0;
}

body.single-page-view #right-front {
  background-image:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.52), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
}

body.single-page-view #right-under {
  display: none;
  background-image:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.52), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
}

body.single-page-view .flap-content {
  width: 100%;
}

body.compact-viewport .viewer-toolbar {
  box-shadow: inset 0 0 0 1px rgba(251, 244, 230, 0.1);
  backdrop-filter: none;
}

body.compact-viewport .page,
body.compact-viewport .flap-content,
body.compact-viewport .transition-page,
body.compact-viewport #right-front,
body.compact-viewport #right-under {
  background-image: linear-gradient(180deg, #fbf4e6 0%, #f1e4cd 100%);
}

body.compact-viewport .page::before {
  opacity: 0.28;
  background:
    linear-gradient(transparent 97%, rgba(93, 41, 44, 0.03) 100%);
  background-size: 100% 24px;
}

body.compact-viewport .single-image-frame {
  padding: 0.5rem;
  border-radius: 20px;
  box-shadow: inset 0 0 0 1px rgba(122, 44, 53, 0.07);
}

body.compact-viewport .single-image {
  border-radius: 16px;
}

body.compact-viewport .fold-gradient {
  display: none;
}

body.compact-viewport .page-number {
  letter-spacing: 0.08rem;
}

.book-container--edge-cover {
  --width: var(--single-width);
  width: var(--single-width);
}

.page--edge-cover {
  left: 0 !important;
  width: 100%;
  border-left: 0;
  background-image:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.52), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
}

.page--edge-cover::after,
.transition-page::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.page--edge-front::after,
.transition-page--front::after {
  background:
    linear-gradient(90deg, rgba(84, 35, 42, 0.28) 0%, rgba(84, 35, 42, 0.14) 4%, transparent 13%);
}

.page--edge-back::after,
.transition-page--back::after {
  background:
    linear-gradient(270deg, rgba(84, 35, 42, 0.28) 0%, rgba(84, 35, 42, 0.14) 4%, transparent 13%);
}

.transition-page {
  left: 0 !important;
  width: 100%;
  display: none;
  z-index: 6;
  border-left: 0;
  pointer-events: none;
  transform-style: preserve-3d;
  backface-visibility: hidden;
  box-shadow: 0 28px 54px rgba(45, 16, 24, 0.2);
  background-image:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.28), transparent 34%),
    radial-gradient(circle at bottom right, rgba(122, 44, 53, 0.05), transparent 25%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.52), transparent 16%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-shadow) 100%);
}

.transition-page.is-front-opening {
  transform-origin: left center;
  animation: frontCoverOpen 620ms cubic-bezier(0.22, 0.61, 0.36, 1) forwards;
}

.transition-page.is-front-closing {
  transform-origin: left center;
  animation: frontCoverClose 620ms cubic-bezier(0.22, 0.61, 0.36, 1) forwards;
}

.transition-page.is-back-opening {
  transform-origin: right center;
  animation: backCoverOpen 620ms cubic-bezier(0.22, 0.61, 0.36, 1) forwards;
}

.transition-page.is-back-closing {
  transform-origin: right center;
  animation: backCoverClose 620ms cubic-bezier(0.22, 0.61, 0.36, 1) forwards;
}

@keyframes frontCoverOpen {
  0% {
    opacity: 1;
    transform: perspective(2200px) rotateY(0deg);
    box-shadow: 0 28px 54px rgba(45, 16, 24, 0.22);
  }

  100% {
    opacity: 0;
    transform: perspective(2200px) rotateY(-178deg);
    box-shadow: 0 40px 60px rgba(45, 16, 24, 0.12);
  }
}

@keyframes frontCoverClose {
  0% {
    opacity: 0;
    transform: perspective(2200px) rotateY(-178deg);
    box-shadow: 0 40px 60px rgba(45, 16, 24, 0.12);
  }

  38% {
    opacity: 1;
  }

  100% {
    opacity: 1;
    transform: perspective(2200px) rotateY(0deg);
    box-shadow: 0 28px 54px rgba(45, 16, 24, 0.22);
  }
}

@keyframes backCoverOpen {
  0% {
    opacity: 1;
    transform: perspective(2200px) rotateY(0deg);
    box-shadow: 0 28px 54px rgba(45, 16, 24, 0.22);
  }

  100% {
    opacity: 0;
    transform: perspective(2200px) rotateY(178deg);
    box-shadow: 0 40px 60px rgba(45, 16, 24, 0.12);
  }
}

@keyframes backCoverClose {
  0% {
    opacity: 0;
    transform: perspective(2200px) rotateY(178deg);
    box-shadow: 0 40px 60px rgba(45, 16, 24, 0.12);
  }

  38% {
    opacity: 1;
  }

  100% {
    opacity: 1;
    transform: perspective(2200px) rotateY(0deg);
    box-shadow: 0 28px 54px rgba(45, 16, 24, 0.22);
  }
}

.sheet {
  position: relative;
  z-index: 1;
  height: 100%;
  min-width: 0;
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  direction: rtl;
  color: var(--ink);
}

.sheet-zoom {
  flex: 1 1 auto;
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  display: grid;
  place-items: center;
  overflow: hidden;
  transform: scale(var(--content-scale));
  transform-origin: center center;
}

.image-sheet {
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  display: grid;
  place-items: center;
  align-self: stretch;
  justify-self: stretch;
}

.single-image-frame {
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  min-width: 0;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-inline: auto;
  padding: clamp(0.35rem, 0.9vw, 0.65rem);
  border-radius: 28px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.26);
  box-shadow:
    inset 0 0 0 1px rgba(122, 44, 53, 0.08),
    0 16px 32px rgba(122, 44, 53, 0.08);
}

.single-image {
  width: 100%;
  height: auto;
  max-width: 100%;
  max-height: 100%;
  min-width: 0;
  min-height: 0;
  display: block;
  object-fit: contain;
  object-position: center center;
  margin-inline: auto;
  border-radius: 22px;
  background: #f7efe0;
  pointer-events: none;
  user-select: none;
  -webkit-user-drag: none;
  opacity: 0;
  transition: opacity 200ms ease;
}

.single-image.loaded {
  opacity: 1;
}

.page-number {
  position: absolute;
  bottom: 1rem;
  color: rgba(93, 41, 44, 0.42);
  font-size: 0.88rem;
  letter-spacing: 0.18rem;
  direction: rtl;
}

#left-front .page-number,
#left-under .page-number {
  left: 1.1rem;
}

#right-front .page-number,
#right-under .page-number {
  right: 1.1rem;
}

.flap-content.is-left .page-number {
  left: 1.1rem;
  right: auto;
}

.flap-content.is-right .page-number {
  right: 1.1rem;
  left: auto;
}

.nav-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 8;
  width: clamp(44px, 5vw, 64px);
  height: clamp(44px, 5vw, 64px);
  border: 0;
  border-radius: 999px;
  background: #fff;
  color: var(--ink);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
  cursor: pointer;
  transition: transform 160ms ease, opacity 160ms ease, background-color 160ms ease;
}

.nav-arrow svg {
  width: clamp(1.2rem, 2vw, 1.45rem);
  height: clamp(1.2rem, 2vw, 1.45rem);
}

.nav-arrow-prev {
  left: clamp(0.35rem, 1vw, 1rem);
}

.nav-arrow-next {
  right: clamp(0.35rem, 1vw, 1rem);
}

.nav-arrow:hover:not(:disabled) {
  transform: translateY(calc(-50% - 1px));
  background: #f0e8da;
}

.nav-arrow:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.whatsapp-float {
  position: fixed;
  top: clamp(0.8rem, 2vw, 1.4rem);
  right: clamp(0.8rem, 2vw, 1.4rem);
  z-index: 24;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3.15rem;
  height: 3.15rem;
  padding: 0;
  border-radius: 50%;
  background: #25d366;
  color: #fff;
  text-decoration: none;
  box-shadow: 0 18px 30px rgba(10, 74, 34, 0.28);
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

.whatsapp-float:hover {
  transform: translateY(-1px);
  box-shadow: 0 22px 34px rgba(10, 74, 34, 0.32);
  background: #1fba59;
}

.whatsapp-float__icon {
  width: 1.55rem;
  height: 1.55rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.whatsapp-float__icon svg {
  width: 100%;
  height: 100%;
  display: block;
  fill: currentColor;
}

@media (max-width: 900px) {
  :root {
    --arrow-clearance: 0px;
    --spread-width: calc(100vw - 1.3rem);
    --single-width: calc(100vw - 1.3rem);
    --height: min(80vh, 780px);
  }

  body {
    --width: var(--single-width);
  }

  #left-front,
  #left-under {
    display: none !important;
  }

  #right-front,
  #right-under {
    left: 0;
    width: 100%;
    border-left: 0;
  }

  .flap-content {
    width: 100%;
  }

  .page-number {
    font-size: 0.76rem;
  }
}

@media (max-width: 640px) {
  :root {
    --spread-width: calc(100vw - 1.4rem);
    --single-width: calc(100vw - 1.4rem);
    --height: min(78vh, 700px);
    --page-padding: 0.8rem;
  }

  .experience {
    padding: 0.45rem;
  }

  .viewer-toolbar {
    gap: 0.4rem;
    width: calc(100% - 0.2rem);
    justify-content: center;
  }

  .display-toggle,
  .spread-status {
    height: 2.9rem;
  }

  .zoom-button {
    width: 2.35rem;
    height: 2.35rem;
  }

  .zoom-value {
    min-width: 3.15rem;
    font-size: 0.8rem;
  }

  .spread-status {
    min-width: 6rem;
    padding: 0 0.75rem;
    font-size: 0.82rem;
  }

  .layout-icon {
    width: 1.25rem;
    height: 1.25rem;
  }

  .status-icon {
    width: 1rem;
    height: 1rem;
  }

  .nav-arrow-prev {
    left: 0.25rem;
  }

  .nav-arrow-next {
    right: 0.25rem;
  }

  .whatsapp-float {
    top: 0.7rem;
    right: 0.7rem;
    width: 3rem;
    height: 3rem;
  }
}

.rotate-overlay {
  display: none;
}

@media (max-width: 768px) and (orientation: portrait) {
  .rotate-overlay {
    display: flex;
    position: fixed;
    inset: 0;
    z-index: 9999;
    align-items: center;
    justify-content: center;
    background:
      radial-gradient(circle at top, rgba(251, 244, 230, 0.1), transparent 30%),
      linear-gradient(135deg, #431520 0%, var(--bg-deep) 42%, #a46d5f 100%);
  }

  .rotate-prompt {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    padding: 2.5rem;
  }

  .rotate-icon {
    width: 72px;
    height: 72px;
    color: var(--paper);
    animation: rotatePhone 2.4s ease-in-out infinite;
  }

  .rotate-text {
    margin: 0;
    color: rgba(251, 244, 230, 0.88);
    font-family: inherit;
    font-size: 1.1rem;
    text-align: center;
    line-height: 1.8;
    direction: rtl;
  }

  .rotate-dismiss {
    border: 1px solid rgba(251, 244, 230, 0.25);
    border-radius: 999px;
    padding: 0.6rem 1.6rem;
    background: rgba(251, 244, 230, 0.1);
    color: rgba(251, 244, 230, 0.75);
    font-family: inherit;
    font-size: 0.92rem;
    cursor: pointer;
    transition: background-color 160ms ease;
  }

  .rotate-dismiss:hover,
  .rotate-dismiss:active {
    background: rgba(251, 244, 230, 0.2);
  }

  .rotate-overlay.dismissed {
    display: none;
  }

  @keyframes rotatePhone {
    0%, 15% {
      transform: rotate(0deg);
      opacity: 1;
    }
    45%, 55% {
      transform: rotate(-90deg);
      opacity: 1;
    }
    70% {
      transform: rotate(-90deg);
      opacity: 0;
    }
    71% {
      transform: rotate(0deg);
      opacity: 0;
    }
    85%, 100% {
      transform: rotate(0deg);
      opacity: 1;
    }
  }

}