:root {
  color-scheme: dark;
  --night: #090a10;
  --night-soft: #11131d;
  --paper: #eee9df;
  --paper-deep: #e3dccf;
  --ink: #17171a;
  --muted: #9699a4;
  --paper-muted: #67635d;
  --violet: #9a8cff;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html, body { min-height: 100%; }

html { background: var(--night); }

body {
  margin: 0;
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 0, rgba(96, 82, 164, 0.13), transparent 34rem),
    linear-gradient(145deg, #0d0f17, var(--night) 58%);
  color: #f3f1ec;
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

button, a { color: inherit; }

button { font: inherit; }

.skip-link {
  position: fixed;
  z-index: 50;
  top: 0.75rem;
  left: 0.75rem;
  transform: translateY(-180%);
  padding: 0.7rem 1rem;
  background: var(--paper);
  color: var(--ink);
  font-weight: 700;
}

.skip-link:focus { transform: translateY(0); }

.reader-toolbar {
  display: grid;
  height: 4.5rem;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 clamp(1rem, 3vw, 3rem);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.reader-brand,
.close-reader {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  text-decoration: none;
  text-transform: uppercase;
}

.reader-brand {
  justify-self: start;
  gap: 0.7rem;
  font-size: 0.75rem;
  font-weight: 750;
  letter-spacing: 0.14em;
}

.brand-mark {
  width: 1.15rem;
  height: 1.15rem;
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 50%;
  box-shadow: inset 0 0 0 0.21rem var(--night), inset 0 0 0 0.27rem rgba(255, 255, 255, 0.42);
}

.reader-title {
  display: flex;
  margin: 0;
  align-items: baseline;
  gap: 0.7rem;
  font-family: var(--serif);
  font-size: 0.9rem;
}

.reader-title span { color: var(--muted); font-style: italic; }
.reader-title strong { font-weight: 400; }

.close-reader {
  justify-self: end;
  gap: 0.45rem;
  color: #b5b7c0;
  font-size: 0.7rem;
  letter-spacing: 0.15em;
}

.close-reader span:first-child { font-size: 1.25rem; font-weight: 300; line-height: 1; }

.reader-stage {
  display: grid;
  height: calc(100svh - 8.5rem);
  grid-template-columns: 3.5rem minmax(0, 70rem) 3.5rem;
  gap: clamp(0.5rem, 2vw, 1.5rem);
  align-items: center;
  justify-content: center;
  padding: 1rem clamp(0.5rem, 2vw, 2rem);
}

.book {
  position: relative;
  isolation: isolate;
  width: 100%;
  height: min(46rem, calc(100svh - 10.5rem));
  perspective: 1800px;
  filter: drop-shadow(0 2.25rem 2.6rem rgba(0, 0, 0, 0.42));
}

.book::before,
.book::after {
  content: "";
  position: absolute;
  z-index: -2;
  top: 0.5rem;
  bottom: -0.45rem;
  width: 50%;
  background: #bab1a2;
}

.book::before { left: 0.45rem; border-radius: 0.2rem 0 0 0.4rem; transform: skewY(-0.35deg); }
.book::after { right: 0.45rem; border-radius: 0 0.2rem 0.4rem 0; transform: skewY(0.35deg); }

.reader-viewport {
  position: absolute;
  inset: 0;
  overflow: hidden;
  border-radius: 0.2rem 0.35rem 0.35rem 0.2rem;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.04), transparent 3%, transparent 47%, rgba(0, 0, 0, 0.075) 50%, transparent 53%, transparent 97%, rgba(0, 0, 0, 0.05)),
    var(--paper);
  scroll-behavior: auto;
}

.chapter-content {
  width: 100%;
  height: 100%;
  padding: clamp(3.2rem, 5vh, 4.5rem) clamp(3.2rem, 5.5vw, 5.2rem);
  column-count: 2;
  column-gap: clamp(6rem, 10vw, 9rem);
  column-fill: auto;
  color: var(--ink);
  font-family: var(--serif);
  font-size: clamp(1.02rem, 1.3vw, 1.18rem);
  line-height: 1.62;
}

.chapter-content h1 {
  margin: 0.15rem 0 2.2rem;
  break-after: avoid;
  font-size: clamp(3rem, 5vw, 5.1rem);
  font-weight: 400;
  letter-spacing: -0.055em;
  line-height: 0.95;
}

.chapter-number {
  margin: 0 0 1rem !important;
  break-after: avoid;
  color: var(--paper-muted);
  font-family: var(--sans) !important;
  font-size: 0.68rem !important;
  font-weight: 750;
  letter-spacing: 0.24em;
  text-transform: uppercase;
}

.chapter-content p {
  margin: 0 0 1.15em;
  orphans: 3;
  widows: 3;
}

.chapter-content em { font-style: italic; }

.chapter-content hr {
  width: 2.6rem;
  margin: 2.3rem auto;
  border: 0;
  border-top: 1px solid #969087;
}

.chapter-end {
  margin-top: 3rem;
  break-inside: avoid;
  text-align: center;
}

.chapter-end p {
  color: var(--paper-muted);
  font-family: var(--sans);
  font-size: 0.68rem;
  font-weight: 750;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.chapter-end a {
  display: inline-flex;
  min-height: 2.9rem;
  align-items: center;
  padding: 0.55rem 1.15rem;
  border: 1px solid rgba(23, 23, 26, 0.38);
  border-radius: 100vmax;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-decoration: none;
  text-transform: uppercase;
}

.page-crease {
  position: absolute;
  z-index: 3;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.18), rgba(255, 255, 255, 0.28), rgba(0, 0, 0, 0.12));
  box-shadow: -1rem 0 2rem rgba(0, 0, 0, 0.08), 1rem 0 2rem rgba(0, 0, 0, 0.08);
  pointer-events: none;
}

.turn-sheet {
  position: absolute;
  z-index: 5;
  top: 0;
  right: 0;
  width: 50%;
  height: 100%;
  transform: rotateY(90deg);
  transform-origin: left center;
  border-radius: 0 0.3rem 0.3rem 0;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.12), transparent 18%, rgba(255, 255, 255, 0.1) 82%, rgba(0, 0, 0, 0.04)),
    var(--paper);
  box-shadow: -1.1rem 0 2rem rgba(0, 0, 0, 0.18);
  backface-visibility: hidden;
  visibility: hidden;
  pointer-events: none;
}

.book.turning-next .turn-sheet { visibility: visible; animation: turn-next 560ms cubic-bezier(0.55, 0.05, 0.2, 1) both; }
.book.turning-prev .turn-sheet { left: 0; right: auto; visibility: visible; transform-origin: right center; animation: turn-prev 560ms cubic-bezier(0.55, 0.05, 0.2, 1) both; }

@keyframes turn-next {
  0% { transform: rotateY(0); }
  48% { box-shadow: -2.5rem 0 3rem rgba(0, 0, 0, 0.28); }
  100% { transform: rotateY(-180deg); }
}

@keyframes turn-prev {
  0% { transform: rotateY(0); }
  48% { box-shadow: 2.5rem 0 3rem rgba(0, 0, 0, 0.28); }
  100% { transform: rotateY(180deg); }
}

.page-control {
  display: grid;
  width: 3.25rem;
  height: 3.25rem;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.035);
  color: #e8e5de;
  cursor: pointer;
  transition: background 180ms ease, color 180ms ease, transform 180ms ease, opacity 180ms ease;
}

.page-control:hover:not(:disabled),
.page-control:focus-visible:not(:disabled) { transform: scale(1.06); background: var(--paper); color: var(--ink); }
.page-control:disabled { opacity: 0.2; cursor: default; }

.reader-footer {
  display: grid;
  height: 4rem;
  grid-template-columns: 1fr minmax(8rem, 18rem) 1fr;
  gap: 1.25rem;
  align-items: center;
  padding: 0 clamp(1rem, 3vw, 3rem);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--muted);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.page-status { margin: 0; }
.reader-hint { margin: 0; text-align: right; }
.reader-progress { height: 1px; overflow: hidden; background: rgba(255, 255, 255, 0.16); }
.reader-progress span { display: block; width: 0; height: 100%; background: #dedad0; transition: width 280ms ease; }

@media (max-width: 800px) {
  .reader-toolbar { height: 4rem; grid-template-columns: 1fr auto; }
  .reader-title { display: none; }
  .close-label { display: none; }
  .reader-stage { height: calc(100svh - 7.5rem); grid-template-columns: 2.65rem minmax(0, 1fr) 2.65rem; gap: 0.25rem; padding: 0.7rem 0.35rem; }
  .book { height: calc(100svh - 8.9rem); max-height: 47rem; }
  .book::before, .book::after { width: 100%; }
  .book::after { display: none; }
  .reader-viewport { border-radius: 0.25rem; background: linear-gradient(90deg, rgba(0, 0, 0, 0.045), transparent 5%, transparent 95%, rgba(0, 0, 0, 0.04)), var(--paper); }
  .chapter-content { padding: clamp(2.25rem, 5vh, 3.4rem) clamp(1.6rem, 7vw, 2.5rem); column-count: 1; column-gap: clamp(3.2rem, 16vw, 5rem); font-size: clamp(1rem, 4.3vw, 1.12rem); line-height: 1.58; }
  .chapter-content h1 { font-size: clamp(3.25rem, 15vw, 5rem); }
  .page-crease { display: none; }
  .turn-sheet { width: 100%; transform-origin: left center; }
  .page-control { width: 2.4rem; height: 2.4rem; font-size: 0.9rem; }
  .reader-footer { height: 3.5rem; grid-template-columns: auto 1fr; padding: 0 1rem; }
  .reader-hint { display: none; }
}

@media (max-height: 660px) and (min-width: 801px) {
  .chapter-content { padding-top: 2.2rem; padding-bottom: 2.2rem; font-size: 1rem; line-height: 1.5; }
}

@media (prefers-reduced-motion: reduce) {
  .turn-sheet { display: none; }
  .reader-progress span, .page-control { transition: none; }
}