:root {
  --bg: #1b1d23;
  --surface: #24272f;
  --ink: #eef0f4;
  --ink-dim: #a7abb8;
  --accent: #d9432e;
  --page-bg: #ffffff;
  --link: #1a56db;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Georgia", "Times New Roman", serif;
  min-height: 100%;
}

.topbar {
  text-align: center;
  padding: 1.5rem 1rem 1rem;
  border-bottom: 1px solid #33363f;
}

.topbar h1 {
  margin: 0;
  font-size: 1.6rem;
  letter-spacing: 0.04em;
  font-weight: 700;
}

.topbar__tag {
  display: inline-block;
  margin-left: 0.5rem;
  font-size: 0.65rem;
  font-family: "Segoe UI", Arial, sans-serif;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--bg);
  background: var(--accent);
  border-radius: 3px;
  padding: 0.15rem 0.4rem;
  vertical-align: middle;
}

.topbar__sub {
  margin: 0.4rem 0 0;
  color: var(--ink-dim);
  font-family: "Segoe UI", Arial, sans-serif;
  font-size: 0.85rem;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem 3rem;
  min-height: 60vh;
}

.loading {
  color: var(--ink-dim);
  font-family: "Segoe UI", Arial, sans-serif;
  padding: 4rem 0;
}

.viewer {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  width: 100%;
}

.book {
  margin: 0 auto;
}

/* Each PDF page rendered as a StPageFlip "page" */
.page {
  background: var(--page-bg);
  overflow: hidden;
  box-shadow: inset 0 0 0 1px rgba(0,0,0,0.08);
}

.page canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.page__links {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.page__link {
  position: absolute;
  pointer-events: auto;
  border-bottom: 2px solid var(--link);
  background: rgba(26, 86, 219, 0.06);
  cursor: pointer;
  transition: background 0.15s ease;
}

.page__link:hover {
  background: rgba(26, 86, 219, 0.16);
}

.controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-family: "Segoe UI", Arial, sans-serif;
}

.controls__btn {
  background: var(--surface);
  color: var(--ink);
  border: 1px solid #3a3d47;
  border-radius: 50%;
  width: 42px;
  height: 42px;
  font-size: 1.3rem;
  line-height: 1;
  cursor: pointer;
}

.controls__btn:hover {
  background: #2c3039;
}

.controls__btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.controls__indicator {
  color: var(--ink-dim);
  font-size: 0.9rem;
  min-width: 4.5rem;
  text-align: center;
}

.footer {
  text-align: center;
  color: var(--ink-dim);
  font-family: "Segoe UI", Arial, sans-serif;
  font-size: 0.78rem;
  padding: 1rem 1rem 2rem;
}