:root {
  --page-ratio: 0.773;
  --spread-ratio: 1.546;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  overflow-x: hidden;
  background: var(--reader-background);
}

body {
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  color: var(--reader-foreground);
  background: var(--reader-body-background, var(--reader-background));
  font-family: var(--reader-body-font);
}

button,
a {
  color: inherit;
  font: inherit;
}

.raster-reader {
  width: min(100% - 2rem, 76rem);
  margin: 0 auto;
  padding: 2.5rem 0 3rem;
}

.reader-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 1rem 2rem;
  width: 100%;
  margin: 0;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--reader-line);
}

.reader-kicker,
.reader-intro,
.reader-note,
.page-status {
  margin: 0;
  color: var(--reader-muted);
  font-family: var(--reader-body-font);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  line-height: 1.5;
  text-transform: uppercase;
}

.reader-header h1 {
  grid-column: 1;
  margin: 0.3rem 0 0;
  font-family: var(--reader-heading-font);
  font-size: clamp(3rem, 8vw, 6.8rem);
  font-weight: var(--reader-heading-weight, 400);
  letter-spacing: var(--reader-heading-spacing, -0.04em);
  line-height: 0.84;
  text-transform: var(--reader-heading-transform, uppercase);
}

.reader-home {
  grid-column: 2;
  grid-row: 1;
  justify-self: end;
  color: var(--reader-accent);
  font-family: var(--reader-body-font);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-decoration: none;
  text-transform: uppercase;
}

.reader-home:hover,
.reader-home:focus-visible {
  color: var(--reader-foreground);
  outline: none;
}

.reader-intro {
  grid-column: 2;
  grid-row: 2;
  max-width: 16rem;
  text-align: right;
}

.reader-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  margin: 0;
  padding: 1.25rem 0;
  border: 0;
}

.control-button {
  min-width: 7rem;
  border: 1px solid var(--reader-line);
  border-radius: 0;
  padding: 0.7rem 0.9rem;
  background: transparent;
  color: var(--reader-foreground);
  cursor: pointer;
  font-family: var(--reader-body-font);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  transition: border-color 180ms ease, color 180ms ease, background 180ms ease;
}

.reader-controls .control-button {
  min-width: 7rem;
  border: 1px solid var(--reader-line);
  padding: 0.7rem 0.9rem;
  font-size: 0.74rem;
  line-height: 1.2;
}

.control-button:hover:not(:disabled),
.control-button:focus-visible:not(:disabled) {
  border-color: var(--reader-accent);
  background: var(--reader-control-hover);
  color: var(--reader-accent);
  outline: none;
}

.control-button:disabled {
  cursor: not-allowed;
  opacity: 0.35;
}

.page-status {
  color: var(--reader-accent);
  text-align: center;
  white-space: nowrap;
}

.page-stage,
body .page-stage.is-cover,
body .page-stage.is-spread {
  --stage-pad: 1.25rem;
  --page-gap: 0.18rem;
  position: relative;
  width: min(96vw, 78rem);
  margin: 0 auto;
  aspect-ratio: var(--spread-ratio);
  padding: var(--stage-pad);
  border: 1px solid var(--reader-line);
  background: var(--reader-stage-background);
  box-shadow: var(--reader-stage-shadow);
  perspective: 2200px;
}

.page-stage::after,
body .page-stage.is-cover::after {
  position: absolute;
  top: var(--stage-pad);
  bottom: var(--stage-pad);
  left: 50%;
  z-index: 7;
  display: block;
  width: 1px;
  background: rgba(0, 0, 0, 0.62);
  box-shadow: 0 0 1rem rgba(0, 0, 0, 0.74);
  content: "";
  pointer-events: none;
}

.page-stage .flip-page,
.page-stage .page,
.page-stage .alt-page {
  position: absolute;
  top: var(--stage-pad);
  right: auto;
  bottom: var(--stage-pad);
  left: auto;
  width: calc(50% - var(--stage-pad) - (var(--page-gap) / 2));
  height: auto;
  overflow: hidden;
  border: 0;
  background: var(--reader-page);
  box-shadow: var(--reader-page-shadow);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: none;
  transition: none;
  backface-visibility: hidden;
}

.page-stage [data-side="left"],
.page-stage .is-left {
  left: var(--stage-pad);
  transform-origin: right center;
}

.page-stage [data-side="right"],
.page-stage .is-right,
.page-stage .cover-page,
.page-stage .page--cover,
.page-stage .alt-cover,
.page-stage [data-page-kind="cover"] {
  left: calc(50% + (var(--page-gap) / 2));
  transform-origin: left center;
}

body .page-stage.is-cover .flip-page.cover-page,
body .page-stage.is-cover .page.page--cover,
body .page-stage.is-cover .alt-page.alt-cover,
body .page-stage.is-cover [data-page-kind="cover"] {
  top: var(--stage-pad);
  right: auto;
  bottom: var(--stage-pad);
  left: calc(50% + (var(--page-gap) / 2));
  width: calc(50% - var(--stage-pad) - (var(--page-gap) / 2));
}

.page-stage .flip-page img,
.page-stage .page img,
.page-stage .alt-page img,
.leaf-face img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  background: var(--reader-page);
  user-select: none;
}

.page-stage .is-current,
.page-stage .is-reveal {
  opacity: 1;
  visibility: visible;
}

.page-stage .is-current {
  z-index: 3;
  pointer-events: auto;
}

.page-stage .is-reveal {
  z-index: 2;
  pointer-events: none;
}

.page-stage .is-turn-source {
  opacity: 0;
  visibility: hidden;
}

.turning-leaf {
  position: absolute;
  top: var(--stage-pad);
  bottom: var(--stage-pad);
  z-index: 9;
  width: calc(50% - var(--stage-pad) - (var(--page-gap) / 2));
  opacity: 0;
  pointer-events: none;
  transform-style: preserve-3d;
  will-change: transform;
}

.turning-leaf--forward {
  left: calc(50% + (var(--page-gap) / 2));
  transform-origin: left center;
}

.turning-leaf--backward {
  left: var(--stage-pad);
  transform-origin: right center;
}

.turning-leaf.is-active {
  opacity: 1;
}

.turning-leaf--forward.is-active {
  animation: reader-turn-forward 820ms cubic-bezier(0.3, 0.03, 0.2, 1) both;
}

.turning-leaf--backward.is-active {
  animation: reader-turn-backward 820ms cubic-bezier(0.3, 0.03, 0.2, 1) both;
}

.leaf-face {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: var(--reader-page);
  box-shadow: 0 0.8rem 2rem rgba(0, 0, 0, 0.54);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.leaf-face--front {
  transform: rotateY(0deg);
}

.leaf-face--back {
  transform: rotateY(180deg);
}

.leaf-face::after {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent 64%, rgba(255, 255, 255, 0.16) 84%, rgba(0, 0, 0, 0.38));
  content: "";
  pointer-events: none;
}

.turning-leaf--backward .leaf-face::after {
  background: linear-gradient(270deg, transparent 64%, rgba(255, 255, 255, 0.16) 84%, rgba(0, 0, 0, 0.38));
}

.page-stage.is-turning::before {
  position: absolute;
  top: var(--stage-pad);
  bottom: var(--stage-pad);
  left: calc(50% - 2.4rem);
  z-index: 8;
  width: 4.8rem;
  background: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.78), transparent 70%);
  content: "";
  pointer-events: none;
  animation: reader-gutter-shadow 820ms ease-in-out both;
}

.reader-note {
  padding-top: 1.25rem;
  text-align: center;
}

.sr-only,
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@keyframes reader-turn-forward {
  0% { transform: rotateY(0deg) translateZ(1px); }
  48% { transform: rotateY(-88deg) translateZ(1.55rem); }
  100% { transform: rotateY(-180deg) translateZ(1px); }
}

@keyframes reader-turn-backward {
  0% { transform: rotateY(0deg) translateZ(1px); }
  48% { transform: rotateY(88deg) translateZ(1.55rem); }
  100% { transform: rotateY(180deg) translateZ(1px); }
}

@keyframes reader-gutter-shadow {
  0%, 100% { opacity: 0.2; transform: scaleX(0.3); }
  50% { opacity: 1; transform: scaleX(1); }
}

@media (max-width: 640px) {
  .raster-reader {
    width: min(100% - 1rem, 76rem);
    padding-top: 1.25rem;
  }

  .reader-header {
    display: block;
  }

  .reader-header h1 {
    max-width: 100%;
    margin-top: 0.7rem;
    overflow-wrap: anywhere;
    font-size: clamp(2.4rem, 14vw, 5.5rem);
  }

  .reader-home {
    display: inline-block;
    margin-bottom: 0.8rem;
  }

  .reader-intro {
    max-width: none;
    margin-top: 0.9rem;
    text-align: left;
  }

  .control-button {
    min-width: 5.5rem;
    padding-inline: 0.55rem;
  }

  .page-stage,
  body .page-stage.is-cover,
  body .page-stage.is-spread {
    --stage-pad: 0.55rem;
    --page-gap: 0;
    width: min(92vw, 38rem);
    aspect-ratio: var(--page-ratio);
  }

  body .page-stage.is-mobile .flip-page,
  body .page-stage.is-mobile .page,
  body .page-stage.is-mobile .alt-page,
  body .page-stage.is-mobile .flip-page.cover-page,
  body .page-stage.is-mobile .page.page--cover,
  body .page-stage.is-mobile .alt-page.alt-cover,
  body .page-stage.is-mobile [data-side="left"],
  body .page-stage.is-mobile [data-side="right"],
  body .page-stage.is-mobile .is-left,
  body .page-stage.is-mobile .is-right,
  body .page-stage.is-mobile [data-page-kind="cover"] {
    left: var(--stage-pad);
    width: calc(100% - (2 * var(--stage-pad)));
  }

  body .page-stage.is-mobile::after,
  body .page-stage.is-mobile.is-turning::before {
    display: none;
  }

  body .page-stage.is-mobile .turning-leaf {
    left: var(--stage-pad);
    width: calc(100% - (2 * var(--stage-pad)));
  }
}

@media (prefers-reduced-motion: reduce) {
  .turning-leaf.is-active,
  .page-stage.is-turning::before {
    animation-duration: 1ms;
  }

  .control-button {
    transition: none;
  }
}