:root {
  --bg-hi: #191919;
  --bg-lo: #101010;
  --line: rgba(255, 255, 255, 0.14);
  --txt: #9c9c9c;
  --txt-dim: #6f6f6f;
  --txt-hi: #f2f2f2;
  --blue: #3e8cff;
  /* w/h of the visible book block; app.js overwrites from the manifest.
     Landscape spread = 2 * page aspect, portrait = 1 * page aspect. */
  --book-ratio: 1.5454;
  /* vertical chrome: bars + paddings + progress, used to fit the book height */
  --chrome-h: 138px;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  background: linear-gradient(180deg, var(--bg-hi) 0%, var(--bg-lo) 100%);
  color: var(--txt);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
  overscroll-behavior: none;
  user-select: none;
  -webkit-user-select: none;
}

.stage {
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px 16px 12px;
}

.bar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.doc-title {
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--txt);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}

.title-short { display: none; }

.spacer { flex: 1; }

.btn {
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  flex: none;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--txt);
  cursor: pointer;
  padding: 0;
  text-decoration: none;
  transition: border-color 0.18s ease, color 0.18s ease, background-color 0.18s ease;
}

.btn:hover {
  color: var(--txt-hi);
  border-color: rgba(62, 140, 255, 0.75);
  background: rgba(62, 140, 255, 0.1);
}

.btn:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}

.btn[disabled] {
  opacity: 0.3;
  cursor: default;
  pointer-events: none;
}

.btn svg {
  width: 17px;
  height: 17px;
  display: block;
}

/* SVG elements do not get the UA [hidden] rule; enforce it. */
.btn svg[hidden] { display: none; }

.book-wrap {
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

/* StPageFlip measures its parent's width and writes inline sizes on the mount
   element, so the fit constraint lives on this frame, not on #book itself. */
.book-frame {
  width: min(100%, calc((100dvh - var(--chrome-h)) * var(--book-ratio)));
}

#book {
  width: 100%;
  opacity: 0;
  transition: opacity 0.5s ease, transform 0.55s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.stage.ready #book { opacity: 1; }

.status {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--txt-dim);
  pointer-events: none;
}

.page {
  position: relative;
  background: #ffffff;
  overflow: hidden;
}

.page img {
  width: 100%;
  height: 100%;
  object-fit: fill;
  display: block;
  pointer-events: none;
}

/* Invisible, selectable text overlaid on the page renders. The layer lives in
   PDF-point coordinates and is scaled to the rendered page size by app.js. */
.text-layer {
  position: absolute;
  left: 0;
  top: 0;
  transform-origin: 0 0;
  z-index: 2;
  cursor: text;
  user-select: text;
  -webkit-user-select: text;
}

.text-layer span {
  position: absolute;
  color: transparent;
  white-space: pre;
  line-height: 1;
  transform-origin: 0 0;
  user-select: text;
  -webkit-user-select: text;
}

.text-layer span::selection {
  background: rgba(62, 140, 255, 0.35);
}

.bar-bottom { justify-content: center; gap: 16px; }

.counter {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--txt);
  font-variant-numeric: tabular-nums;
  min-width: 84px;
  text-align: center;
}

.progress {
  flex: none;
  height: 2px;
  border-radius: 1px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
}

#progress-fill {
  height: 100%;
  width: 0;
  background: var(--blue);
  transition: width 0.45s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.noscript {
  position: fixed;
  inset: auto 16px 16px;
  text-align: center;
  font-size: 13px;
  color: var(--txt-hi);
}

.noscript a { color: var(--blue); }

@media (max-width: 640px) {
  .stage { padding: 10px 12px 10px; gap: 6px; --chrome-h: 122px; }
  .title-long { display: none; }
  .title-short { display: inline; }
  .btn { width: 32px; height: 32px; }
  .bar-bottom { gap: 10px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}

.stage.noanim, .stage.noanim * { transition: none !important; }