:root {
  --paper: #f4ead5;
  --paper-2: #ebe0c1;
  --ink: #1a2330;
  --ink-2: #2d3a4a;
  --dim: #6b6754;
  --accent: #2f8a4f;
  --accent-glow: #43c47a;
  --warn: #b8642e;
  --rule: #1a23301a;
  --rail-bg: #1a2330;
  --rail-thumb: #43c47a;
  --topbar-h: 38px;
  --bottombar-h: 26px;
  --rail-w: 22px;
  --text-scale: 1;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  width: 600px;
  height: 600px;
  overflow: hidden;
  background: var(--ink);
  color: var(--ink);
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  user-select: none;
}

#app {
  position: relative;
  width: 600px;
  height: 600px;
  background:
    radial-gradient(ellipse at 30% 0%, #faf2dd 0%, #f4ead5 55%, #e9dfba 100%);
  background-color: var(--paper);
  overflow: hidden;
}

/* paper grain */
#app::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(circle at 12% 18%, #00000008 0 1px, transparent 1px),
    radial-gradient(circle at 78% 62%, #00000006 0 1px, transparent 1px),
    radial-gradient(circle at 42% 88%, #00000008 0 1px, transparent 1px);
  background-size: 9px 9px, 13px 13px, 11px 11px;
  mix-blend-mode: multiply;
  opacity: 0.7;
}

/* ─── topbar ─────────────────────────────────────────────────── */
.topbar {
  position: absolute;
  top: 0; left: 0; right: var(--rail-w);
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 14px 0 14px;
  background: linear-gradient(to bottom, #1a2330 0%, #1a2330 88%, #1a233000 100%);
  color: var(--paper);
  z-index: 10;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 11px;
  letter-spacing: 0.18em;
  font-weight: 700;
}
.brand-mark {
  color: var(--accent-glow);
  font-size: 13px;
  text-shadow: 0 0 6px var(--accent-glow);
}
.brand-text { color: var(--paper); }
.page-pill {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--accent-glow);
  border: 1px solid #43c47a55;
  padding: 3px 8px;
  border-radius: 3px;
  background: #43c47a14;
}
.size-pill {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 10px;
  letter-spacing: 0.16em;
  color: #b5c5dd;
  border: 1px solid #b5c5dd33;
  padding: 3px 8px;
  border-radius: 3px;
  background: #b5c5dd0e;
  margin-right: 8px;
  transition: color 0.18s, border-color 0.18s, background 0.18s;
}
.size-pill.flash {
  color: var(--accent-glow);
  border-color: var(--accent-glow);
  background: #43c47a22;
}

/* ─── bottombar ─────────────────────────────────────────────── */
.bottombar {
  position: absolute;
  bottom: 0; left: 0; right: var(--rail-w);
  height: var(--bottombar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 14px;
  background: #1a2330;
  color: var(--paper);
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 10px;
  letter-spacing: 0.1em;
  z-index: 10;
}
.bottombar .cue { color: var(--paper); }
.bottombar .dim { color: #8a9bb3; }
.bottombar .status {
  color: var(--accent-glow);
  font-weight: 700;
  letter-spacing: 0.16em;
}
kbd {
  display: inline-block;
  padding: 0 4px;
  border: 1px solid #43c47a66;
  border-radius: 2px;
  font-family: inherit;
  font-size: 9px;
  color: var(--accent-glow);
  background: #43c47a14;
  vertical-align: 1px;
}

/* ─── tilt rail (right edge) ────────────────────────────────── */
.tilt-rail {
  position: absolute;
  top: 0; right: 0;
  width: var(--rail-w);
  height: 600px;
  background: var(--rail-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 6px 0;
  z-index: 11;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color: #8a9bb3;
}
.rail-cap {
  font-size: 10px;
  line-height: 1;
  color: #43c47a99;
}
.rail-track {
  flex: 1;
  width: 4px;
  margin: 6px 0;
  background: #2d3a4a;
  border-radius: 2px;
  position: relative;
  overflow: visible;
}
.rail-thumb {
  position: absolute;
  left: -3px;
  width: 10px;
  height: 10px;
  background: var(--accent-glow);
  border-radius: 50%;
  top: 0%;
  transform: translateY(-50%);
  box-shadow: 0 0 8px var(--accent-glow);
  transition: top 0.05s linear;
}
.rail-readout {
  font-size: 8px;
  letter-spacing: 0.1em;
  color: var(--accent-glow);
  margin-top: 2px;
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}

/* ─── book / scroller ───────────────────────────────────────── */
.book {
  position: absolute;
  top: var(--topbar-h);
  bottom: var(--bottombar-h);
  left: 0;
  right: var(--rail-w);
  overflow-y: auto;
  overflow-x: hidden;
  scroll-behavior: auto;
  scrollbar-width: none;
}
.book::-webkit-scrollbar { display: none; }

/* ─── pages ─────────────────────────────────────────────────── */
.page {
  display: none;
  padding: 18px 22px 6px 22px;
}
.page.active { display: block; }

.chapter-num {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(13px * var(--text-scale));
  letter-spacing: 0.32em;
  color: var(--accent);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.chapter-title {
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  font-size: calc(34px * var(--text-scale));
  line-height: 1.1;
  font-weight: 600;
  font-style: italic;
  color: var(--ink);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 14px;
}

.byline {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(12px * var(--text-scale));
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin: -6px 0 14px 0;
  text-align: left;
  opacity: 0.85;
}
.byline strong {
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0.12em;
}
.byline-end {
  text-align: center;
  margin: 4px 0 18px 0;
  opacity: 1;
}

.illustration {
  margin: 8px 0 16px 0;
  background: #1a233008;
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 8px;
  display: flex;
  justify-content: center;
}
.illustration svg {
  width: 100%;
  max-width: 460px;
  height: auto;
  display: block;
}

.page p {
  font-size: calc(20px * var(--text-scale));
  line-height: 1.5;
  margin-bottom: 16px;
  color: var(--ink);
  text-align: left;
  hyphens: auto;
}
.page p strong {
  font-weight: 700;
  color: var(--ink);
}
.page p em {
  font-style: italic;
  color: var(--ink-2);
}
.page p.callout {
  font-size: calc(23px * var(--text-scale));
  font-style: italic;
  text-align: center;
  margin: 18px 16px;
  color: var(--ink);
  border-left: 3px solid var(--accent-glow);
  padding-left: 14px;
  line-height: 1.35;
}
.page p.whisper {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(17px * var(--text-scale));
  letter-spacing: 0.16em;
  text-align: center;
  color: var(--accent);
  margin: 16px 0 20px 0;
  opacity: 0.9;
}
.page p.fin {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(15px * var(--text-scale));
  letter-spacing: 0.4em;
  text-align: center;
  color: var(--dim);
  margin: 26px 0 10px 0;
  text-transform: uppercase;
}

.morse {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(17px * var(--text-scale));
  letter-spacing: 0.3em;
  color: var(--accent);
  background: #43c47a14;
  padding: 2px 8px;
  border-radius: 2px;
  border: 1px solid #43c47a33;
}
.ping {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-style: normal;
  font-size: calc(18px * var(--text-scale));
  padding: 2px 6px;
  background: #43c47a14;
  border-radius: 2px;
}

/* ─── page-end / next button ───────────────────────────────── */
.page-end {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px dashed var(--rule);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding-bottom: 14px;
}
.end-cue {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(12px * var(--text-scale));
  letter-spacing: 0.18em;
  color: var(--dim);
  text-transform: uppercase;
  text-align: center;
}
.next-btn {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: calc(16px * var(--text-scale));
  letter-spacing: 0.22em;
  font-weight: 700;
  padding: 14px 28px;
  background: var(--ink);
  color: var(--paper);
  border: 2px solid var(--ink);
  border-radius: 4px;
  cursor: pointer;
  transition: transform 0.08s, box-shadow 0.16s, background 0.16s, color 0.16s;
}
.next-btn:hover,
.next-btn.armed {
  background: var(--accent-glow);
  color: var(--ink);
  border-color: var(--accent-glow);
  box-shadow: 0 0 0 4px #43c47a33, 0 0 18px #43c47a66;
  transform: translateY(-1px);
}
.next-btn:active { transform: translateY(0); }

/* ─── overlay (start) ──────────────────────────────────────── */
.overlay {
  position: absolute;
  inset: 0;
  background: rgba(26, 35, 48, 0.92);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(2px);
}
.overlay.hidden { display: none; }
.overlay-card {
  background: var(--paper);
  color: var(--ink);
  padding: 28px 32px;
  border-radius: 6px;
  box-shadow: 0 0 0 2px var(--accent-glow), 0 12px 40px #0008;
  text-align: center;
  max-width: 460px;
}
.overlay-mark {
  font-size: 28px;
  color: var(--accent);
  margin-bottom: 6px;
  text-shadow: 0 0 12px var(--accent-glow);
}
.overlay-title {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 16px;
  letter-spacing: 0.24em;
  font-weight: 700;
  margin-bottom: 6px;
}
.overlay-sub {
  font-style: italic;
  font-size: 14px;
  color: var(--dim);
  margin-bottom: 6px;
}
.overlay-byline {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 11px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}
.overlay-body {
  font-size: 13px;
  line-height: 1.5;
  margin-bottom: 18px;
}
.overlay-btn {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  letter-spacing: 0.24em;
  font-weight: 700;
  padding: 10px 22px;
  background: var(--ink);
  color: var(--paper);
  border: 2px solid var(--accent-glow);
  border-radius: 4px;
  cursor: pointer;
}
.overlay-btn:hover {
  background: var(--accent-glow);
  color: var(--ink);
}

/* a focusable affordance for d-pad */
.focusable:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--accent-glow), 0 0 16px #43c47a66;
}