/* AI Crash Course, Call 1. Versorix. */
@font-face {
  font-family: "Pirulen";
  src: url("fonts/Pirulen-Light.ttf") format("truetype");
  font-weight: 300;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Pirulen";
  src: url("fonts/Pirulen-Italic.ttf") format("truetype");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

:root {
  --black: #111110;
  --surface: #1a1917;
  --surface-2: #232220;
  --line: #2f2e2a;
  --ink: #f3f1ea;
  --muted: #a8a59b;
  --dim: #6e6c64;
  --volt: #ffe100;
  --volt-ink: #111110;
  --display: "Pirulen", "Inter", sans-serif;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "SF Mono", Consolas, monospace;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  height: 100%;
  background: var(--black);
  color: var(--ink);
  font-family: var(--body);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}
button { font: inherit; }

/* ---------- Stage ---------- */
#viewport {
  position: fixed;
  inset: 0;
  overflow: hidden;
  touch-action: pan-y;
}
#stage {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 1920px;
  height: 1080px;
  transform-origin: 0 0;
  background: var(--black);
  overflow: hidden;
}
#grain {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 50;
  opacity: 0.045;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='220' height='220'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  mix-blend-mode: screen;
}

/* chrome */
#chrome {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 40;
}
#chrome .logo {
  position: absolute;
  left: 120px;
  top: 64px;
  height: 36px;
  width: auto;
}
#chrome .counter {
  position: absolute;
  right: 120px;
  top: 64px;
  font-size: 22px;
  font-weight: 500;
  color: var(--dim);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}
#chrome .counter b { color: var(--muted); font-weight: 500; }
#progress {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 6px;
  width: 0%;
  background: var(--volt);
  transition: width 0.5s var(--ease);
}

/* ---------- Slides ---------- */
.slide {
  position: absolute;
  inset: 0;
  padding: 150px 120px 120px;
  visibility: hidden;
  opacity: 0;
}
.slide.active { visibility: visible; opacity: 1; }
.slide .notes { display: none; }

[data-step] { opacity: 0; }

.kicker {
  font-family: var(--display);
  font-weight: 300;
  font-size: 22px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--volt);
  margin: 0 0 28px;
}
.title {
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 44px;
  line-height: 1.1;
  margin: 0 0 24px;
  color: var(--ink);
}
.big {
  font-size: 88px;
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.025em;
  margin: 0;
  max-width: 1500px;
}
.big.sm { font-size: 72px; }
.huge {
  font-size: 128px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.035em;
  margin: 0;
}
.hollow {
  color: transparent;
  -webkit-text-stroke: 3px var(--ink);
}
.line {
  font-size: 40px;
  font-weight: 500;
  line-height: 1.25;
  color: var(--ink);
  margin: 0;
  max-width: 1400px;
}
.line.volt { color: var(--volt); }
.sub {
  font-size: 28px;
  line-height: 1.4;
  color: var(--muted);
  margin: 0;
  max-width: 1200px;
}
.foot {
  position: absolute;
  left: 120px;
  bottom: 110px;
  right: 120px;
}
strong { font-weight: 800; color: var(--ink); }

/* ---------- Copy card ---------- */
.prompt {
  position: relative;
  background: var(--surface);
  border: 2px solid var(--line);
  padding: 40px 48px 40px;
  max-width: 1680px;
}
.prompt pre {
  margin: 0;
  font-family: var(--mono);
  font-size: 26px;
  line-height: 1.5;
  white-space: pre-wrap;
  color: var(--ink);
  padding-right: 200px;
}
.prompt pre .fill { color: var(--volt); }
.copy-btn {
  position: absolute;
  right: 32px;
  top: 32px;
  background: var(--volt);
  color: var(--volt-ink);
  border: 0;
  padding: 14px 24px;
  font-size: 20px;
  font-weight: 700;
  cursor: pointer;
  pointer-events: auto;
  transition: transform 0.25s var(--ease), background 0.25s var(--ease);
  min-width: 150px;
}
.copy-btn:hover { transform: translateY(-2px); }
.copy-btn:active { transform: translateY(0); }
.copy-btn.done { background: var(--ink); }
.copy-btn:focus-visible { outline: 3px solid var(--ink); outline-offset: 3px; }

/* ---------- 01 Cover ---------- */
.s01 { padding-top: 220px; }
.s01 .display {
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  font-size: 128px;
  line-height: 1.06;
  letter-spacing: 0.02em;
  margin: 0;
}
.s01 .display .w { display: block; }
.caret {
  display: inline-block;
  width: 0.14em;
  height: 0.9em;
  background: var(--volt);
  vertical-align: -0.08em;
  margin-left: 0.18em;
  animation: blink 1.1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }
.s01 .cover-foot {
  position: absolute;
  left: 120px;
  bottom: 110px;
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 24px;
  color: var(--muted);
}
.s01 .cover-foot img { height: 44px; }
.s01 .cover-foot i { width: 2px; height: 36px; background: var(--line); display: block; }
.s01 .grid {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 46%;
  background-image: radial-gradient(var(--line) 1.5px, transparent 1.6px);
  background-size: 36px 36px;
  -webkit-mask-image: linear-gradient(to left, #000 20%, transparent 100%);
  mask-image: linear-gradient(to left, #000 20%, transparent 100%);
  opacity: 0.7;
}

/* ---------- 02 Hands ---------- */
.s02 .hands {
  position: absolute;
  left: 120px;
  right: 120px;
  bottom: 120px;
  height: 340px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  border-bottom: 2px solid var(--line);
}
.s02 .hand { width: 92px; height: 115px; fill: var(--volt); }
.s02 .hand:nth-child(odd) { height: 150px; width: 120px; }
.s02 .hand:nth-child(3n) { fill: var(--ink); }

/* ---------- 03 Chat ---------- */
.s03 .chat {
  position: absolute;
  left: 120px;
  top: 150px;
  width: 1120px;
  height: 790px;
  background: var(--surface);
  border: 2px solid var(--line);
  overflow: hidden;
}
.chat-bar {
  height: 56px;
  border-bottom: 2px solid var(--line);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 24px;
  color: var(--dim);
  font-size: 20px;
}
.chat-bar i { width: 14px; height: 14px; border-radius: 50%; background: var(--line); }
.chat-bar span { margin-left: 14px; }
.msg {
  margin: 40px 48px 0;
  font-size: 30px;
  line-height: 1.45;
}
.msg.user {
  margin-left: 300px;
  background: var(--surface-2);
  border: 2px solid var(--line);
  padding: 24px 32px;
  min-height: 94px;
}
.msg.user .caret { height: 1em; vertical-align: -0.15em; }
.msg.ai p { margin: 0 0 20px; color: var(--muted); }
.msg.ai .skel { display: flex; flex-direction: column; gap: 14px; margin: 0 0 24px; }
.msg.ai .skel i { display: block; height: 18px; background: var(--surface-2); border-radius: 3px; }
.s03 .side {
  position: absolute;
  left: 1300px;
  top: 150px;
  width: 500px;
}
.stamp {
  position: absolute;
  left: 1120px;
  top: 580px;
  transform: rotate(-9deg);
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  font-size: 58px;
  line-height: 1.1;
  color: var(--volt);
  border: 8px solid var(--volt);
  padding: 20px 36px;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

/* ---------- 04 Statement ---------- */
.s04 { padding-top: 300px; }
.s04 .huge + .huge { margin-top: 24px; }

/* ---------- 05 Pillars ---------- */
.s05 .pillars {
  position: absolute;
  left: 120px;
  right: 120px;
  bottom: 120px;
  height: 560px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 120px;
  border-bottom: 3px solid var(--line);
}
.s05 .pillar-wrap { position: relative; }
.s05 .pillar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 420px;
  background: var(--volt);
  transform-origin: bottom center;
  transform: scaleY(0);
}
.s05 .pillar-wrap:nth-child(2) .pillar { background: var(--ink); }
.s05 .pillar-label {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 300px;
  text-align: center;
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  font-size: 60px;
  letter-spacing: 0.06em;
  color: var(--volt-ink);
  opacity: 0;
}
.s05 .pillar-cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 110px;
  text-align: center;
  font-size: 30px;
  font-weight: 600;
  color: var(--volt-ink);
  opacity: 0;
  padding: 0 40px;
}
.s05 .thats {
  position: absolute;
  left: 120px;
  bottom: 40px;
  font-size: 34px;
  font-weight: 700;
  margin: 0;
}

/* ---------- 06 Not ---------- */
.s06 .cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  margin-top: 80px;
}
.s06 .card {
  position: relative;
  border: 2px solid var(--line);
  background: var(--surface);
  padding: 56px 56px 64px;
  min-height: 480px;
}
.s06 .card .label {
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  font-size: 52px;
  letter-spacing: 0.04em;
  margin: 0 0 32px;
  line-height: 1.15;
}
.s06 .card p { font-size: 34px; line-height: 1.4; color: var(--muted); margin: 0; }
.s06 .card .x {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: visible;
}
.s06 .card .x line {
  stroke: var(--volt);
  stroke-width: 18;
  stroke-linecap: round;
}
.s06 .card .not {
  position: absolute;
  left: 40px;
  top: -34px;
  background: var(--volt);
  color: var(--volt-ink);
  font-family: var(--display);
  font-size: 30px;
  padding: 10px 22px;
  letter-spacing: 0.1em;
  opacity: 0;
}

/* ---------- 07 Equation ---------- */
.s07 .eqs {
  position: absolute;
  left: 120px;
  right: 120px;
  top: 330px;
  height: 260px;
}
.s07 .eq {
  position: absolute;
  left: 0;
  top: 0;
  font-size: 112px;
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1;
  white-space: nowrap;
  opacity: 0;
}
.s07 .eq .op { color: var(--dim); font-weight: 400; margin: 0 0.18em; }
.s07 .eq .res { color: var(--volt); }
.s07 .eq.ghost .res { color: var(--dim); }
.s07 .foot { bottom: 140px; }

/* ---------- 08 Iceberg ---------- */
.s08 .scene {
  position: absolute;
  left: 120px;
  right: 120px;
  top: 250px;
  bottom: 60px;
}
.s08 svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.s08 .typed-tag {
  position: absolute;
  left: 0;
  top: 40px;
  width: 520px;
}
.s08 .typed-tag small {
  display: block;
  font-size: 20px;
  color: var(--dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}
.s08 .typed-tag q {
  font-size: 30px;
  line-height: 1.35;
  font-weight: 600;
  quotes: "\201C" "\201D";
}
.s08 .lab {
  position: absolute;
  background: var(--surface-2);
  border: 2px solid var(--line);
  color: var(--ink);
  font-size: 26px;
  font-weight: 600;
  padding: 12px 22px;
  white-space: nowrap;
}
.s08 .tipline {
  position: absolute;
  right: 0;
  top: 40px;
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-align: right;
  width: 500px;
  line-height: 1.1;
}

/* ---------- 09 Habits ---------- */
.s09 .cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  margin-top: 30px;
}
.s09 h3 {
  font-size: 54px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
  line-height: 1.1;
}
.s09 .ex { font-size: 26px; color: var(--muted); margin: 0 0 32px; }
.s09 table {
  width: 100%;
  border-collapse: collapse;
  font-size: 26px;
}
.s09 th {
  text-align: left;
  font-weight: 500;
  color: var(--dim);
  padding: 8px 0 14px;
  border-bottom: 2px solid var(--line);
  font-size: 20px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.s09 td { padding: 16px 0; border-bottom: 1px solid var(--line); }
.s09 td.blank { color: var(--dim); }
.s09 td.blank i { display: block; width: 70%; height: 2px; border-top: 2px dotted var(--dim); }
.s09 .bubbles { display: flex; flex-direction: column; gap: 22px; }
.s09 .bub {
  font-size: 28px;
  padding: 22px 30px;
  border: 2px solid var(--line);
  background: var(--surface);
  max-width: 560px;
  position: relative;
}
.s09 .bub.ghost { color: var(--dim); border-style: dashed; }
.s09 .bub.ghost::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  top: 50%;
  height: 4px;
  background: var(--volt);
  transform: rotate(-2deg);
}
.s09 .bub.ai { background: var(--surface-2); color: var(--ink); align-self: flex-end; }
.s09 .bub .tag {
  position: absolute;
  right: -10px;
  top: -18px;
  background: var(--volt);
  color: var(--volt-ink);
  font-size: 18px;
  font-weight: 700;
  padding: 6px 12px;
}
.s09 .foot { bottom: 100px; }

/* ---------- 10 Cheat code ---------- */
.s10 .prompt { margin-top: 56px; }

/* ---------- 11 Three columns ---------- */
.s11 .cols {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 40px;
  margin-top: 20px;
  height: 600px;
}
.s11 .col {
  border-top: 4px solid var(--line);
  padding-top: 24px;
  position: relative;
}
.s11 .col.hot { border-top-color: var(--volt); }
.s11 .v {
  font-family: var(--display);
  font-weight: 300;
  font-size: 22px;
  letter-spacing: 0.1em;
  color: var(--dim);
  margin: 0 0 8px;
}
.s11 .col.hot .v { color: var(--volt); }
.s11 h3 { font-size: 40px; font-weight: 800; margin: 0 0 24px; letter-spacing: -0.02em; }
.s11 .out {
  font-size: 23px;
  line-height: 1.4;
  color: var(--muted);
}
.s11 .skel { display: flex; flex-direction: column; gap: 12px; margin-top: 18px; }
.s11 .skel i { display: block; height: 14px; background: var(--surface-2); border-radius: 3px; }
.s11 .badge {
  display: inline-block;
  border: 2px solid var(--line);
  color: var(--dim);
  font-size: 20px;
  padding: 6px 14px;
  margin-top: 28px;
}
.s11 ol { margin: 0; padding: 0; list-style: none; counter-reset: q; }
.s11 ol li {
  counter-increment: q;
  font-size: 25px;
  line-height: 1.3;
  padding: 11px 0 11px 56px;
  border-bottom: 1px solid var(--line);
  position: relative;
  color: var(--ink);
}
.s11 ol li::before {
  content: counter(q);
  position: absolute;
  left: 0;
  top: 11px;
  color: var(--volt);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}
.s11 .brief { font-size: 22px; }
.s11 .brief .row { display: grid; grid-template-columns: 130px 1fr; gap: 16px; align-items: center; padding: 11px 0; border-bottom: 1px solid var(--line); }
.s11 .brief .row b { color: var(--ink); font-weight: 700; }
.s11 .brief .row i { display: block; height: 14px; background: var(--surface-2); border-radius: 3px; }
.s11 .foot { bottom: 100px; }

/* ---------- 12 Six questions ---------- */
.s12 .qs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 100px;
  margin-top: 20px;
}
.s12 .q {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 28px;
  align-items: start;
  padding: 40px 0;
  border-bottom: 2px solid var(--line);
}
.s12 .q svg { width: 56px; height: 56px; stroke: var(--volt); fill: none; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; margin-top: 4px; }
.s12 .q b { display: block; font-size: 40px; font-weight: 800; letter-spacing: -0.015em; line-height: 1.15; }
.s12 .q span { display: block; font-size: 26px; color: var(--muted); margin-top: 8px; line-height: 1.35; }
.s12 .q small { color: var(--dim); font-size: 22px; font-weight: 500; display: block; margin-bottom: 4px; }

/* ---------- 13 Why ---------- */
.s13 .pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  margin-top: 30px;
}
.s13 .instr {
  font-size: 30px;
  line-height: 1.35;
  padding: 24px 32px;
  background: var(--surface-2);
  border: 2px solid var(--line);
  margin: 0 0 32px;
  min-height: 128px;
}
.s13 .doc {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}
.s13 .page {
  border: 2px solid var(--line);
  background: var(--surface);
  padding: 24px;
  height: 300px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.s13 .bar { height: 14px; background: var(--dim); border-radius: 3px; }
.s13 .bar.ok { background: var(--volt); }
.s13 .verdict { font-size: 28px; font-weight: 700; margin: 24px 0 0; }
.s13 .verdict.good { color: var(--volt); }
.s13 .foot { bottom: 90px; }

/* ---------- 14 Wall ---------- */
.s14 .scene {
  position: absolute;
  left: 120px;
  right: 120px;
  top: 300px;
  height: 420px;
}
.s14 svg { width: 100%; height: 100%; overflow: visible; }
.s14 .p-try, .s14 .p-around { fill: none; stroke-width: 10; stroke-linecap: round; stroke-linejoin: round; }
.s14 .p-try { stroke: var(--dim); }
.s14 .p-around { stroke: var(--volt); }
.s14 .wall rect { fill: var(--surface-2); stroke: var(--line); stroke-width: 3; }
.s14 .wall text { fill: var(--muted); font-family: var(--display); font-size: 30px; letter-spacing: 0.1em; }
.s14 .goal { fill: var(--volt); }
.s14 .start { fill: var(--ink); }
.s14 .foot { bottom: 70px; }
.s14 .foot .prompt { max-width: 1680px; }

/* ---------- 15 Train ---------- */
.s15 .signs { margin-top: 20px; }
.s15 .signs li {
  list-style: none;
  font-size: 40px;
  font-weight: 600;
  line-height: 1.2;
  padding: 18px 0 18px 44px;
  position: relative;
  max-width: 900px;
}
.s15 .signs li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 32px;
  width: 20px;
  height: 20px;
  background: var(--volt);
}
.s15 .signs { padding: 0; margin: 20px 0 0; }
.s15 .scene {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 60px;
  height: 260px;
}
.s15 svg, .s16 svg { width: 100%; height: 100%; }
.rail { stroke: var(--dim); stroke-width: 6; fill: none; }
.sleeper { stroke: var(--line); stroke-width: 10; }
.train .body { fill: var(--volt); }
.train .cab { fill: var(--ink); }
.train .wheel { fill: var(--black); stroke: var(--muted); stroke-width: 6; }
.train .win { fill: var(--black); }
.s15 .wall rect { fill: var(--surface-2); stroke: var(--line); stroke-width: 3; }

/* ---------- 16 Branches ---------- */
.s16 .scene {
  position: absolute;
  left: 0;
  right: 0;
  top: 230px;
  height: 300px;
}
.s16 .branch { fill: none; stroke: var(--volt); stroke-width: 6; }
.s16 .moves {
  position: absolute;
  left: 120px;
  right: 120px;
  bottom: 170px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 80px;
}
.s16 .move h3 { font-size: 40px; font-weight: 800; margin: 0 0 18px; letter-spacing: -0.02em; }
.s16 .move p { font-size: 28px; color: var(--muted); line-height: 1.4; margin: 0; }
.s16 .move .prompt { padding: 28px 36px; }
.s16 .move .prompt pre { font-size: 24px; padding-right: 180px; }
.s16 .move .copy-btn { top: 24px; right: 24px; padding: 10px 18px; font-size: 18px; min-width: 120px; }

/* ---------- 17 Feedback ---------- */
.s17 .pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  margin-top: 30px;
}
.s17 .try { position: relative; }
.s17 .try small {
  display: block;
  font-size: 20px;
  color: var(--dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.s17 .bub {
  font-size: 32px;
  line-height: 1.4;
  padding: 30px 36px;
  background: var(--surface-2);
  border: 2px solid var(--line);
  margin: 0;
  min-height: 230px;
}
.s17 .bub u { text-decoration: none; border-bottom: 4px solid var(--volt); padding-bottom: 2px; }
.s17 .result {
  margin: 28px 0 0;
  font-size: 34px;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 18px;
}
.s17 .result::before { content: ""; width: 60px; height: 4px; background: var(--dim); }
.s17 .result.good { color: var(--volt); }
.s17 .result.good::before { background: var(--volt); }
.s17 .foot { bottom: 100px; }

/* ---------- 18 Stop ---------- */
.s18 .stops { margin: 20px 0 0; padding: 0; list-style: none; }
.s18 .stops li {
  position: relative;
  display: inline-block;
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
  padding: 14px 0;
  margin-bottom: 6px;
  clear: both;
}
.s18 .stops li { display: table; }
.s18 .stops li .strike {
  position: absolute;
  left: -12px;
  right: -12px;
  top: 50%;
  height: 10px;
  margin-top: -5px;
  background: var(--volt);
  transform: scaleX(0);
  transform-origin: left center;
}
.s18 .stops li.dead { color: var(--dim); }
.s18 .foot { bottom: 110px; }

/* ---------- 19 Four rules ---------- */
.s19 .rules { margin: 10px 0 0; padding: 0; list-style: none; }
.s19 .rules li {
  font-size: 96px;
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1.05;
  padding: 10px 0 10px 70px;
  position: relative;
}
.s19 .rules li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 48px;
  width: 36px;
  height: 36px;
  background: var(--volt);
}

/* ---------- 20 CTA ---------- */
.s20 .big { max-width: 1100px; }
.s20 .sub { margin-top: 28px; max-width: 1150px; }
.s20 .cta { margin-top: 56px; }
.s20 .url {
  display: inline-block;
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--volt-ink);
  background: var(--volt);
  text-decoration: none;
  padding: 18px 36px;
  pointer-events: auto;
}
.s20 .qr {
  position: absolute;
  right: 120px;
  top: 220px;
  width: 440px;
  height: 440px;
  padding: 24px;
  background: var(--ink);
}
.s20 .qr svg { width: 100%; height: 100%; display: block; }
.s20 .foot { display: flex; align-items: flex-end; justify-content: space-between; bottom: 90px; }
.s20 .foot img { height: 40px; }
.s20 .hw { font-size: 30px; color: var(--muted); margin: 0; max-width: 1100px; line-height: 1.4; }
.s20 .hw b { color: var(--ink); font-weight: 800; }

/* ---------- Notes panel ---------- */
#notes {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  max-height: 38vh;
  overflow: auto;
  background: rgba(17, 17, 16, 0.94);
  border-top: 2px solid var(--volt);
  padding: 20px 28px 28px;
  font-size: 18px;
  line-height: 1.5;
  color: var(--ink);
  z-index: 100;
  transform: translateY(100%);
  transition: transform 0.35s var(--ease);
}
#notes.open { transform: translateY(0); }
#notes h4 { margin: 0 0 10px; font-size: 13px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--volt); font-weight: 600; }
#notes p { margin: 0 0 10px; max-width: 70ch; }
#notes b { color: var(--volt); font-weight: 700; }
#help {
  position: fixed;
  right: 16px;
  bottom: 14px;
  font-size: 12px;
  color: var(--dim);
  z-index: 90;
  letter-spacing: 0.02em;
  user-select: none;
}
#help kbd { color: var(--muted); font-family: var(--mono); }

/* ---------- Presenter view ---------- */
body.presenter #viewport, body.presenter #help { display: none; }
#pres { display: none; }
body.presenter #pres {
  display: block;
  padding: 32px 40px;
  min-height: 100vh;
  overflow: auto;
}
#pres .ph { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 2px solid var(--volt); padding-bottom: 12px; margin-bottom: 20px; }
#pres .ph b { font-family: var(--display); font-weight: 300; font-size: 26px; letter-spacing: 0.06em; }
#pres .ph span { color: var(--muted); font-size: 18px; }
#pres .pn { font-size: 24px; line-height: 1.55; max-width: 80ch; }
#pres .pn p { margin: 0 0 16px; }
#pres .pn b { color: var(--volt); }
#pres .hint { color: var(--dim); font-size: 14px; margin-top: 30px; }

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  .caret { animation: none; }
  #progress, .copy-btn, #notes { transition: none; }
}

@media (max-width: 700px) {
  #help { display: none; }
}