:root {
  --book-page-width: 720px;
  --book-page-height: 960px;
  --book-page-aspect-ratio: 3 / 4;
  --book-spread-aspect-ratio: 3 / 2;
  --book-spread-width: 1440px;
  --book-scale: 1;
  --book-rendered-width: 1440px;
  --book-rendered-height: 960px;
  --nepal-font-handwriting: "Xiaolai SC", "PingFang SC", cursive;
  --paper: #f7f3e9;
  --paper-soft: #fffdf6;
  --paper-warm: #fff8e8;
  --paper-muted: #e9dfce;
  --ink: #143d38;
  --seal: #d86a58;
  --shadow: rgba(30, 25, 18, 0.18);
  color: var(--ink);
  font-family:
    "Inter Variable",
    var(--nepal-font-handwriting),
    "PingFang SC",
    system-ui,
    sans-serif;
}

* {
  box-sizing: border-box;
}

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

body {
  background:
    radial-gradient(circle at 22% 18%, rgba(216, 106, 88, 0.11), transparent 24%),
    linear-gradient(135deg, #f9f5eb 0%, #ebe4d4 100%);
}

.nepal-reader {
  display: grid;
  width: 100%;
  height: 100%;
  place-items: center;
  padding: 36px;
}

.nepal-reader__viewport {
  position: relative;
  width: var(--book-rendered-width);
  height: var(--book-rendered-height);
}

.nepal-reader__stage {
  position: absolute;
  top: 0;
  left: 0;
  width: var(--book-spread-width);
  height: var(--book-page-height);
  transform: scale(var(--book-scale));
  transform-origin: top left;
}

.nepal-reader__book {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 8px;
  filter: drop-shadow(0 24px 44px var(--shadow));
}

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

.stf__parent {
  margin-inline: auto;
}

.stf__block {
  overflow: visible;
  perspective: 3200px;
}

.book-page {
  position: absolute;
  inset: 0;
  display: none;
  overflow: hidden;
  border: 1px solid rgba(20, 61, 56, 0.16);
  border-radius: 8px;
  background: var(--paper);
  box-shadow:
    inset 0 0 70px rgba(91, 64, 32, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.74);
  transform-origin: left center;
  container-type: size;
}

.book-page::before {
  position: absolute;
  z-index: 20;
  inset: 0;
  pointer-events: none;
  content: "";
  background-image:
    url("./textures/paper-fiber-mask.webp"),
    repeating-linear-gradient(
      0deg,
      rgba(72, 52, 26, 0.07) 0 1px,
      transparent 1px 13px
    );
  background-size: 360px 360px, 100% 100%;
  mix-blend-mode: multiply;
  opacity: 0.28;
}

.page {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  padding: 56px;
  color: var(--ink);
}

.page h1,
.page h2,
.page p {
  margin-top: 0;
}

.page h1 {
  max-width: 12em;
  font-family: var(--nepal-font-handwriting);
  font-size: clamp(34px, 5cqh, 54px);
  line-height: 1.12;
}

.page p {
  font-size: 18px;
  line-height: 1.72;
}

.preview-error {
  display: grid;
  width: min(560px, calc(100vw - 48px));
  min-height: 220px;
  place-items: center;
  padding: 28px;
  border: 1px solid rgba(216, 106, 88, 0.32);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  color: #802819;
  text-align: center;
}