:root {
  --bg: #070b16;
  --panel: rgba(15, 23, 42, 0.78);
  --panel-strong: rgba(15, 23, 42, 0.94);
  --text: #f8fafc;
  --muted: #a8b3c7;
  --cyan: #38bdf8;
  --blue: #60a5fa;
  --green: #34d399;
  --gold: #fde68a;
  --pink: #f472b6;
  --violet: #a78bfa;
  --border: rgba(148,163,184,.22);
}
* { box-sizing: border-box; }
html, body { margin: 0; width: 100%; height: 100%; background: var(--bg); color: var(--text); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; overflow: hidden; }
body::before { content: ""; position: fixed; inset: 0; background:
  radial-gradient(circle at 18% 14%, rgba(56,189,248,.26), transparent 28%),
  radial-gradient(circle at 84% 18%, rgba(167,139,250,.20), transparent 32%),
  radial-gradient(circle at 50% 94%, rgba(52,211,153,.16), transparent 30%),
  linear-gradient(135deg, #050816 0%, #0b1020 48%, #06091a 100%); z-index: -3; }
body::after { content: ""; position: fixed; inset: 0; background-image: linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px); background-size: 42px 42px; mask-image: radial-gradient(circle at center, black 0%, transparent 80%); z-index: -2; }
.deck-shell { position: relative; width: 100vw; height: 100vh; }
.slide { position: absolute; inset: 0; padding: 72px 86px 78px; opacity: 0; transform: translate3d(40px, 0, 0) scale(.985); filter: blur(8px); transition: opacity .62s ease, transform .72s cubic-bezier(.2,.9,.1,1), filter .62s ease; pointer-events: none; display: grid; place-items: center; }
.slide.active { opacity: 1; transform: translate3d(0, 0, 0) scale(1); filter: blur(0); pointer-events: auto; }
.slide.past { transform: translate3d(-34px, 0, 0) scale(.985); }
.slide-inner { width: min(1180px, 94vw); max-height: calc(100vh - 160px); overflow: auto; padding: 46px 52px 42px; border: 1px solid var(--border); border-radius: 34px; background: linear-gradient(180deg, rgba(15,23,42,.79), rgba(15,23,42,.58)); box-shadow: 0 32px 110px rgba(0,0,0,.42), inset 0 1px 0 rgba(255,255,255,.06); backdrop-filter: blur(18px); }
.slide-inner::-webkit-scrollbar { width: 8px; }
.slide-inner::-webkit-scrollbar-thumb { background: rgba(148,163,184,.25); border-radius: 999px; }
.slide-kicker { position: fixed; top: 25px; left: 34px; color: var(--muted); font-size: 13px; letter-spacing: .18em; text-transform: uppercase; display: flex; gap: 12px; align-items: center; z-index: 10; }
.slide-kicker::before { content: ""; width: 9px; height: 9px; border-radius: 99px; background: var(--green); box-shadow: 0 0 24px var(--green); }
.slide-count { position: fixed; top: 24px; right: 34px; z-index: 10; color: var(--muted); font-size: 14px; }
.slide h1 { font-size: clamp(44px, 6vw, 82px); line-height: .95; margin: 0 0 26px; letter-spacing: -0.055em; color: #fff; text-shadow: 0 0 38px rgba(56,189,248,.13); }
.slide h2 { font-size: clamp(30px, 3.6vw, 48px); line-height: 1.08; margin: 0 0 26px; color: #a7f3d0; letter-spacing: -0.025em; }
.slide h3 { color: #93c5fd; font-size: 28px; margin: 22px 0 12px; }
.slide p, .slide li { font-size: clamp(22px, 2.25vw, 32px); line-height: 1.32; color: #e5edf9; }
.slide ul, .slide ol { padding-left: 1.1em; }
.slide li { margin: .32em 0; }
.slide strong { color: var(--gold); }
.slide blockquote { margin: 24px 0; padding: 26px 30px; border-left: 7px solid var(--cyan); background: rgba(8, 47, 73, .36); border-radius: 22px; box-shadow: inset 0 1px 0 rgba(255,255,255,.08); }
.slide blockquote p { color: #e0f2fe; font-size: clamp(30px, 4vw, 52px); line-height: 1.16; margin: 0; }
.slide table { width: 100%; border-collapse: separate; border-spacing: 0; margin: 24px 0; overflow: hidden; border-radius: 20px; border: 1px solid var(--border); background: rgba(2,6,23,.45); }
.slide th, .slide td { padding: 16px 18px; border-bottom: 1px solid rgba(148,163,184,.18); font-size: clamp(16px, 1.6vw, 23px); vertical-align: top; }
.slide th { color: var(--gold); background: rgba(15,23,42,.94); text-align: left; }
.slide tr:last-child td { border-bottom: none; }
.slide code { background: rgba(2,6,23,.82); color: #fde68a; padding: .14em .35em; border-radius: 8px; }
.slide pre { background: rgba(2,6,23,.86); border: 1px solid rgba(148,163,184,.22); border-radius: 20px; padding: 22px 26px; overflow: auto; box-shadow: inset 0 1px 0 rgba(255,255,255,.04); }
.slide pre code { background: transparent; padding: 0; font-size: clamp(18px, 2vw, 30px); color: #d9f99d; }
.progress { position: fixed; bottom: 0; left: 0; height: 5px; background: linear-gradient(90deg, var(--cyan), var(--green), var(--gold)); width: 0%; z-index: 30; box-shadow: 0 0 20px rgba(56,189,248,.65); transition: width .3s ease; }
.controls { position: fixed; bottom: 18px; left: 50%; transform: translateX(-50%); display: flex; align-items: center; gap: 10px; padding: 10px; border: 1px solid rgba(148,163,184,.22); border-radius: 999px; background: rgba(2,6,23,.58); backdrop-filter: blur(18px); z-index: 50; box-shadow: 0 12px 42px rgba(0,0,0,.32); }
.controls button, .deck-button { border: 0; color: #e5edf9; background: rgba(30,41,59,.72); padding: 10px 14px; border-radius: 999px; font-weight: 700; cursor: pointer; transition: transform .16s ease, background .16s ease; }
.controls button:hover, .deck-button:hover { transform: translateY(-1px); background: rgba(51,65,85,.95); }
.controls .primary { background: linear-gradient(135deg, #2563eb, #0891b2); }
.status-pill { position: fixed; left: 34px; bottom: 22px; color: var(--muted); font-size: 13px; z-index: 50; background: rgba(2,6,23,.48); border: 1px solid rgba(148,163,184,.18); padding: 9px 12px; border-radius: 999px; backdrop-filter: blur(14px); max-width: 34vw; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.notes-panel { position: fixed; top: 70px; right: 28px; width: min(420px, 36vw); max-height: calc(100vh - 145px); overflow: auto; padding: 20px; background: rgba(2,6,23,.90); border: 1px solid rgba(148,163,184,.25); border-radius: 24px; box-shadow: 0 22px 80px rgba(0,0,0,.48); z-index: 70; transform: translateX(calc(100% + 44px)); transition: transform .32s ease; }
.notes-panel.open { transform: translateX(0); }
.notes-panel h3 { margin-top: 0; color: var(--gold); }
.notes-panel p { font-size: 15px; line-height: 1.45; color: #dbeafe; white-space: pre-wrap; }
.narration-panel { position: fixed; right: 34px; bottom: 22px; width: min(430px, 34vw); font-size: 13px; line-height: 1.35; color: #dbeafe; background: rgba(2,6,23,.52); border: 1px solid rgba(148,163,184,.18); border-radius: 18px; padding: 12px 14px; z-index: 49; backdrop-filter: blur(14px); }
.hidden { display: none !important; }
.intro-choice { min-height: 100vh; display: grid; place-items: center; padding: 48px; }
.choice-wrap { width: min(1160px, 94vw); }
.choice-title { font-size: clamp(46px, 7vw, 90px); line-height: .92; letter-spacing: -.06em; margin: 0 0 20px; }
.choice-sub { font-size: 24px; color: var(--muted); max-width: 850px; line-height: 1.35; }
.choice-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px; margin-top: 34px; }
.choice-card { display: block; min-height: 260px; padding: 30px; border-radius: 32px; color: inherit; text-decoration: none; border: 1px solid rgba(148,163,184,.22); background: linear-gradient(180deg, rgba(15,23,42,.82), rgba(15,23,42,.54)); box-shadow: 0 32px 100px rgba(0,0,0,.32); transition: transform .25s ease, border-color .25s ease; }
.choice-card:hover { transform: translateY(-8px); border-color: rgba(56,189,248,.62); }
.choice-card h2 { margin: 0 0 16px; color: #fff; font-size: 34px; }
.choice-card p { color: #cbd5e1; font-size: 20px; line-height: 1.35; }
.choice-card .tag { color: var(--green); text-transform: uppercase; letter-spacing: .15em; font-size: 12px; font-weight: 900; }
.shortcut-grid { margin-top: 24px; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; color: var(--muted); font-size: 14px; }
.shortcut-grid span { border: 1px solid rgba(148,163,184,.18); border-radius: 14px; padding: 10px 12px; background: rgba(15,23,42,.45); }
@media (max-width: 860px) { .choice-grid { grid-template-columns: 1fr; } .slide { padding: 56px 18px 88px; } .slide-inner { padding: 30px 26px; } .narration-panel, .status-pill { max-width: 90vw; left: 18px; right: 18px; width: auto; } .notes-panel { width: calc(100vw - 38px); right: 18px; } .controls { gap: 4px; } .controls button { padding: 9px 10px; font-size: 12px; } }


/* v2: smart dense-slide layout, scroll hints, transitions, and speed controls */
.slide-inner { scroll-behavior: smooth; overscroll-behavior: contain; }
.slide-inner.overflowing { overflow-y: auto; padding-right: 38px; }
.slide-inner.overflowing::after {
  content: "";
  position: sticky;
  display: block;
  bottom: -43px;
  height: 54px;
  margin: 4px -20px -42px;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(15,23,42,0), rgba(15,23,42,.94));
}
.slide-inner.overflowing > h1:first-child,
.slide-inner.overflowing > h2:first-child {
  position: sticky;
  top: -18px;
  z-index: 4;
  padding: 18px 0 14px;
  margin-top: -18px;
  background: linear-gradient(180deg, rgba(15,23,42,.96), rgba(15,23,42,.88) 78%, rgba(15,23,42,0));
  backdrop-filter: blur(14px);
}
.slide-inner.two-col-list ul,
.slide-inner.two-col-list ol { columns: 2; column-gap: 44px; }
.slide-inner.two-col-list li { break-inside: avoid; }
.slide-inner.dense { padding-top: 36px; padding-bottom: 34px; }
.slide-inner.dense h1 { font-size: clamp(34px, 4.2vw, 62px); margin-bottom: 18px; }
.slide-inner.dense h2 { font-size: clamp(26px, 3vw, 40px); margin-bottom: 18px; }
.slide-inner.dense h3 { font-size: 23px; margin: 14px 0 8px; }
.slide-inner.dense p, .slide-inner.dense li { font-size: clamp(18px, 1.7vw, 25px); line-height: 1.23; }
.slide-inner.dense blockquote { padding: 18px 22px; margin: 16px 0; }
.slide-inner.dense blockquote p { font-size: clamp(24px, 3vw, 40px); }
.slide-inner.dense pre { padding: 16px 20px; margin: 12px 0; }
.slide-inner.dense pre code { font-size: clamp(15px, 1.55vw, 22px); }
.slide-inner.dense table { margin: 14px 0; }
.slide-inner.dense th, .slide-inner.dense td { padding: 11px 13px; font-size: clamp(14px, 1.3vw, 18px); }
.slide-inner.very-dense { padding-top: 30px; padding-bottom: 30px; }
.slide-inner.very-dense h1 { font-size: clamp(30px, 3.7vw, 52px); margin-bottom: 14px; }
.slide-inner.very-dense h2 { font-size: clamp(23px, 2.5vw, 34px); margin-bottom: 14px; }
.slide-inner.very-dense p, .slide-inner.very-dense li { font-size: clamp(16px, 1.35vw, 21px); line-height: 1.18; margin-top: .22em; margin-bottom: .22em; }
.slide-inner.very-dense blockquote p { font-size: clamp(22px, 2.6vw, 34px); }
.slide-inner.very-dense ul, .slide-inner.very-dense ol { margin-top: 10px; margin-bottom: 10px; }
.slide-inner li, .slide-inner p, .slide-inner a { overflow-wrap: anywhere; }
.scroll-hint {
  display: none;
  position: fixed;
  left: 50%;
  bottom: 78px;
  transform: translateX(-50%);
  z-index: 52;
  font-size: 13px;
  color: #e0f2fe;
  border: 1px solid rgba(56,189,248,.28);
  background: rgba(2,6,23,.62);
  padding: 9px 13px;
  border-radius: 999px;
  backdrop-filter: blur(14px);
  box-shadow: 0 10px 34px rgba(0,0,0,.3);
}
body.has-overflow .scroll-hint { display: block; animation: pulseHint 1.8s ease-in-out infinite; }
@keyframes pulseHint { 0%,100%{ opacity:.55; transform: translateX(-50%) translateY(0); } 50%{ opacity:1; transform: translateX(-50%) translateY(-3px); } }
.duration-badge {
  position: fixed;
  top: 54px;
  right: 34px;
  z-index: 10;
  color: #cbd5e1;
  font-size: 12px;
  border: 1px solid rgba(148,163,184,.18);
  background: rgba(2,6,23,.48);
  border-radius: 999px;
  padding: 7px 10px;
  backdrop-filter: blur(12px);
}
.controls select {
  color: #e5edf9;
  background: rgba(30,41,59,.72);
  border: 0;
  border-radius: 999px;
  padding: 10px 12px;
  font-weight: 800;
  cursor: pointer;
}
.controls .secondary { background: rgba(15,23,42,.82); color: #cbd5e1; }
body[data-transition="fade"] .slide { transform: scale(1); filter: blur(0); transition: opacity .48s ease; }
body[data-transition="fade"] .slide.past { transform: scale(1); }
body[data-transition="zoom"] .slide { transform: scale(.92); filter: blur(14px); transition: opacity .58s ease, transform .72s cubic-bezier(.22,1,.36,1), filter .62s ease; }
body[data-transition="zoom"] .slide.active { transform: scale(1); filter: blur(0); }
body[data-transition="slide"] .slide { transform: translate3d(72px, 0, 0); filter: blur(0); transition: opacity .52s ease, transform .64s cubic-bezier(.2,.88,.2,1); }
body[data-transition="slide"] .slide.past { transform: translate3d(-72px, 0, 0); }
body[data-transition="tilt"] .slide { transform: perspective(1100px) rotateY(9deg) translateX(60px) scale(.985); transform-origin: center; filter: blur(7px); transition: opacity .58s ease, transform .74s cubic-bezier(.2,.9,.1,1), filter .58s ease; }
body[data-transition="tilt"] .slide.active { transform: perspective(1100px) rotateY(0deg) translateX(0) scale(1); filter: blur(0); }
body[data-transition="tilt"] .slide.past { transform: perspective(1100px) rotateY(-9deg) translateX(-60px) scale(.985); }
body[data-transition="diffusion"] .slide { transform: translate3d(40px,0,0) scale(.985); filter: blur(8px); }
@media (max-width: 1080px) {
  .narration-panel { display: none; }
  .duration-badge { right: 20px; }
  .slide-inner.two-col-list ul, .slide-inner.two-col-list ol { columns: 1; }
}
@media (max-width: 860px) {
  .duration-badge { top: 52px; right: 18px; }
  .scroll-hint { bottom: 72px; }
  .controls select, .controls .secondary, #transitionBtn, #scrollBtn { display: none; }
}

/* v3: polished icon controls, safe crisp defaults, no persistent status noise */
.slide { filter: blur(0); }
body[data-transition="fade"] .slide { transform: scale(1); filter: blur(0); transition: opacity .42s ease, transform .42s ease; }
body[data-transition="fade"] .slide.active { transform: scale(1); filter: blur(0); }
body[data-transition="slide"] .slide { transform: translate3d(46px, 0, 0) scale(.995); filter: blur(0); transition: opacity .46s ease, transform .56s cubic-bezier(.2,.88,.2,1); }
body[data-transition="slide"] .slide.active { transform: translate3d(0,0,0) scale(1); filter: blur(0); }
body[data-transition="slide"] .slide.past { transform: translate3d(-46px, 0, 0) scale(.995); }
body[data-transition="lift"] .slide { transform: translate3d(0, 28px, 0) scale(.985); filter: blur(0); transition: opacity .5s ease, transform .62s cubic-bezier(.2,.9,.1,1); }
body[data-transition="lift"] .slide.active { transform: translate3d(0,0,0) scale(1); filter: blur(0); }
body[data-transition="zoom"] .slide.active,
body[data-transition="tilt"] .slide.active,
body[data-transition="diffusion"] .slide.active { filter: blur(0); opacity: 1; }
body[data-transition="diffusion"] .slide { transform: translate3d(28px,0,0) scale(.992); filter: blur(5px); transition: opacity .48s ease, transform .56s cubic-bezier(.2,.9,.1,1), filter .44s ease; }
body[data-transition="diffusion"] .slide.active { transform: translate3d(0,0,0) scale(1); filter: blur(0); }
body[data-transition="diffusion"] .slide.past { transform: translate3d(-28px,0,0) scale(.992); filter: blur(3px); }

.controls {
  bottom: 20px;
  gap: 6px;
  padding: 7px 8px;
  border-color: rgba(203,213,225,.16);
  background: rgba(2,6,23,.34);
  box-shadow: 0 16px 48px rgba(0,0,0,.24);
  backdrop-filter: blur(22px) saturate(125%);
  opacity: .82;
  transition: opacity .18s ease, transform .18s ease, background .18s ease;
}
.controls:hover { opacity: 1; background: rgba(2,6,23,.58); transform: translateX(-50%) translateY(-1px); }
.controls button.icon-btn,
.icon-btn {
  width: 38px;
  height: 38px;
  display: inline-grid;
  place-items: center;
  padding: 0;
  border: 1px solid rgba(255,255,255,.07);
  background: rgba(15,23,42,.42);
  color: #f8fafc;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.07);
}
.controls button.icon-btn:hover,
.icon-btn:hover {
  transform: translateY(-1px) scale(1.035);
  background: rgba(30,41,59,.82);
  border-color: rgba(148,163,184,.28);
}
.controls .icon-btn svg { width: 19px; height: 19px; fill: currentColor; display: block; }
.controls .icon-btn.primary {
  width: 44px;
  height: 44px;
  color: #fff;
  background: radial-gradient(circle at 35% 25%, rgba(255,255,255,.32), transparent 28%), linear-gradient(135deg, #2563eb, #06b6d4);
  box-shadow: 0 0 0 1px rgba(255,255,255,.08), 0 10px 32px rgba(37,99,235,.32);
}
.controls .icon-btn.primary.is-playing { background: linear-gradient(135deg, #dc2626, #f97316); box-shadow: 0 10px 32px rgba(249,115,22,.25); }
.controls .icon-btn.soft { color: #dbeafe; background: rgba(15,23,42,.32); }
.controls .icon-btn.off,
.controls .icon-btn.muted { opacity: .55; }
.speed-control {
  height: 38px;
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 0 5px 0 9px;
  border-radius: 999px;
  color: #e5edf9;
  border: 1px solid rgba(255,255,255,.07);
  background: rgba(15,23,42,.38);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.06);
}
.speed-mark { color: #93c5fd; font-weight: 900; font-size: 15px; line-height: 1; }
.controls select {
  height: 30px;
  min-width: 54px;
  padding: 0 4px;
  background: transparent;
  color: #f8fafc;
  font-size: 13px;
  font-weight: 800;
  outline: none;
  appearance: auto;
}
.status-pill {
  display: none;
  left: 24px;
  bottom: 26px;
  max-width: 38vw;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity .18s ease, transform .18s ease;
}
.status-pill.visible { display: block; opacity: 1; transform: translateY(0); }
.narration-panel { display: none; }
.duration-badge { opacity: .78; }
.scroll-hint { bottom: 74px; opacity: .82; }
@media (max-width: 980px) {
  .controls { max-width: calc(100vw - 26px); overflow-x: auto; }
  .controls::-webkit-scrollbar { display: none; }
  .controls .icon-btn { flex: 0 0 auto; }
}
@media (max-width: 860px) {
  .controls button.icon-btn, .icon-btn { width: 36px; height: 36px; }
  .controls .icon-btn.primary { width: 42px; height: 42px; }
  .speed-control, #transitionBtn, #scrollBtn { display: none; }
}


/* v4: social polish and slower, more perceptible transitions */
body[data-transition="fade"] .slide {
  transform: scale(1);
  filter: blur(0);
  transition: opacity .78s ease, transform .78s ease;
}
body[data-transition="slide"] .slide {
  transform: translate3d(58px, 0, 0) scale(.993);
  filter: blur(0);
  transition: opacity .76s ease, transform .94s cubic-bezier(.16,.88,.22,1);
}
body[data-transition="slide"] .slide.past { transform: translate3d(-58px, 0, 0) scale(.993); }
body[data-transition="lift"] .slide {
  transform: translate3d(0, 34px, 0) scale(.984);
  filter: blur(0);
  transition: opacity .78s ease, transform .98s cubic-bezier(.16,.88,.22,1);
}
body[data-transition="zoom"] .slide {
  transform: scale(.955);
  filter: blur(0);
  transition: opacity .82s ease, transform 1.02s cubic-bezier(.16,.88,.22,1);
}
body[data-transition="tilt"] .slide {
  transform: perspective(1200px) rotateY(7deg) translateX(52px) scale(.986);
  transform-origin: center;
  filter: blur(0);
  transition: opacity .82s ease, transform 1.06s cubic-bezier(.16,.88,.22,1);
}
body[data-transition="tilt"] .slide.past { transform: perspective(1200px) rotateY(-7deg) translateX(-52px) scale(.986); }
body[data-transition="diffusion"] .slide {
  transform: translate3d(34px,0,0) scale(.992);
  filter: blur(2px);
  transition: opacity .82s ease, transform .98s cubic-bezier(.16,.88,.22,1), filter .84s ease;
}
body[data-transition="diffusion"] .slide.active { transform: translate3d(0,0,0) scale(1); filter: blur(0); }
body[data-transition="diffusion"] .slide.past { transform: translate3d(-34px,0,0) scale(.992); filter: blur(1px); }
.choice-title { text-shadow: 0 0 58px rgba(56,189,248,.20); }
.choice-sub { max-width: 940px; }
.choice-card { position: relative; overflow: hidden; }
.choice-card::after {
  content: "";
  position: absolute;
  inset: auto -20% -55% 30%;
  height: 180px;
  background: radial-gradient(circle, rgba(56,189,248,.18), transparent 68%);
  pointer-events: none;
}