/* AI Crash Course, call 2: Talk to it. 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;
}
.display {
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  font-size: 128px;
  line-height: 1.06;
  letter-spacing: 0.02em;
  margin: 0;
}
.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: 1500px;
}
.line b { font-weight: 800; }
.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); }

/* why-it-does-that block, shared (full border, no side stripe) */
.whybox {
  background: var(--surface);
  border: 2px solid var(--line);
  padding: 24px 30px 26px;
  font-size: 26px;
  line-height: 1.4;
  color: var(--ink);
}
.whybox small {
  display: block;
  font-family: var(--display);
  font-weight: 300;
  font-size: 16px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--volt);
  margin-bottom: 10px;
}

/* cover-style footer, shared */
.cover-foot {
  position: absolute;
  left: 120px;
  bottom: 110px;
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 24px;
  color: var(--muted);
}
.cover-foot img { height: 44px; }
.cover-foot i { width: 2px; height: 36px; background: var(--line); 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; } }

/* ---------- 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); }
.prompt.small { padding: 28px 40px; }
.prompt.small pre { font-size: 24px; padding-right: 170px; }
.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;
}
.prompt.small .copy-btn { top: 22px; right: 24px; padding: 10px 18px; font-size: 18px; min-width: 120px; }
.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 ---------- */
.cover { padding-top: 250px; }
.cover .display { font-size: 190px; line-height: 0.98; }
.cover .display .caret { width: 0.12em; height: 0.8em; vertical-align: -0.02em; }
.cover .recap {
  margin: 56px 0 0;
  font-size: 40px;
  font-weight: 500;
  line-height: 1.3;
  color: var(--muted);
}
.cover .callnum {
  position: absolute;
  right: 110px;
  top: 150px;
  font-family: var(--display);
  font-weight: 300;
  font-size: 760px;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 3px var(--line);
  user-select: none;
}
.cover .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 The empty ask ---------- */
.empty .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; }
.empty .side {
  position: absolute;
  left: 1300px;
  top: 150px;
  width: 500px;
}
.empty .stamp {
  position: relative;
  display: inline-block;
  margin-top: 300px;
  margin-left: -20px;
  transform: rotate(-9deg);
  font-family: var(--display);
  font-weight: 300;
  text-transform: uppercase;
  font-size: 40px;
  line-height: 1.1;
  color: var(--volt);
  border: 8px solid var(--volt);
  padding: 20px 36px;
  letter-spacing: 0.05em;
  white-space: nowrap;
}
.empty .verdict-wrap {
  position: absolute;
  left: 120px;
  right: 120px;
  top: 380px;
}
.empty .verdict-wrap .huge + .huge { margin-top: 24px; }

/* ---------- 03 Multiplier ---------- */
.multiply .drill { margin-top: 28px; font-size: 30px; }
.multiply .eqs {
  position: absolute;
  left: 120px;
  right: 120px;
  top: 500px;
  height: 260px;
}
.multiply .eqn {
  position: absolute;
  left: 0;
  top: 0;
  font-size: 180px;
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1;
  white-space: nowrap;
  opacity: 0;
}
.multiply .eqn .op { color: var(--dim); font-weight: 400; margin: 0 0.16em; }
.multiply .eqn .res { color: var(--volt); }
.multiply .foot { bottom: 110px; }

/* ---------- 04 Iceberg ---------- */
.berg .scene {
  position: absolute;
  left: 0;
  right: 0;
  top: 230px;
  bottom: 0;
}
.berg svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.berg .typed-tag {
  position: absolute;
  left: 120px;
  top: 40px;
  width: 520px;
}
.berg .typed-tag small {
  display: block;
  font-size: 20px;
  color: var(--dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}
.berg .typed-tag q {
  font-size: 30px;
  line-height: 1.35;
  font-weight: 600;
  quotes: "\201C" "\201D";
}
.berg .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;
}
.berg .tipline {
  position: absolute;
  right: 120px;
  top: 30px;
  font-size: 60px;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-align: right;
  width: 520px;
  line-height: 1.1;
  margin: 0;
}
.berg .whybox {
  position: absolute;
  right: 120px;
  top: 190px;
  width: 520px;
  font-size: 23px;
}

/* ---------- 05 Cheat code ---------- */
.cheat .prompt { margin-top: 64px; padding: 48px 56px; }
.cheat .prompt pre { font-size: 30px; }
.cheat .foot { bottom: 130px; }

/* ---------- 06 The brief ---------- */
.brief .card6 {
  position: relative;
  margin-top: 56px;
  background: var(--surface);
  border: 2px solid var(--line);
  padding: 40px 48px 36px;
}
.brief .card6 ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 72px;
  counter-reset: s;
}
.brief .card6 li {
  counter-increment: s;
  position: relative;
  padding: 20px 0 20px 64px;
  border-bottom: 1px solid var(--line);
}
.brief .card6 li:nth-last-child(-n+2) { border-bottom: 0; }
.brief .card6 li::before {
  content: counter(s);
  position: absolute;
  left: 0;
  top: 20px;
  width: 40px;
  height: 40px;
  line-height: 40px;
  text-align: center;
  background: var(--volt);
  color: var(--volt-ink);
  font-weight: 800;
  font-size: 22px;
}
.brief .card6 li b { display: block; font-size: 32px; font-weight: 800; letter-spacing: -0.015em; line-height: 1.15; }
.brief .card6 li span { display: block; font-size: 22px; color: var(--muted); margin-top: 6px; line-height: 1.35; }
.brief .card6 .copy-btn { top: -26px; right: 40px; }

/* ---------- 07 Always another way ---------- */
.wall .scene {
  position: absolute;
  left: 120px;
  right: 120px;
  top: 360px;
  height: 440px;
}
.wall svg { width: 100%; height: 100%; overflow: visible; }
.wall .p-try, .wall .p-around { fill: none; stroke-width: 10; stroke-linecap: round; stroke-linejoin: round; }
.wall .p-try { stroke: var(--dim); }
.wall .p-around { stroke: var(--volt); }
.wallg rect { fill: var(--surface-2); stroke: var(--line); stroke-width: 3; }
.wallg line { stroke: var(--line); stroke-width: 3; }
.wall .wallg text { fill: var(--muted); font-family: var(--display); font-size: 30px; letter-spacing: 0.1em; text-transform: uppercase; }
.wall .goal { fill: var(--volt); }
.wall .start { fill: var(--ink); }
.wall .foot { bottom: 90px; }

/* ---------- 08 Tunnel vision ---------- */
.tunnel .two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  margin-top: 0;
}
.tunnel .tells { margin-top: 24px; font-size: 26px; max-width: 760px; }
.tunnel .left .whybox { margin-top: 32px; font-size: 24px; max-width: 780px; }
.tunnel .right { padding-top: 10px; }
.tunnel .move + .move { margin-top: 36px; }
.tunnel .move h3 { font-size: 36px; font-weight: 800; margin: 0 0 16px; letter-spacing: -0.02em; }
.tunnel .move p { font-size: 28px; color: var(--muted); line-height: 1.4; margin: 0; }
.tunnel .scene {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 40px;
  height: 220px;
}
.tunnel 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); }

/* ---------- 09 Feedback ---------- */
.feedback .pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  margin-top: 40px;
}
.feedback .try { position: relative; }
.feedback .try small {
  display: block;
  font-size: 20px;
  color: var(--dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.feedback .bub {
  font-size: 36px;
  line-height: 1.4;
  padding: 36px 40px;
  background: var(--surface-2);
  border: 2px solid var(--line);
  margin: 0;
  min-height: 280px;
}
.feedback .bub u { text-decoration: none; border-bottom: 4px solid var(--volt); padding-bottom: 2px; }
.feedback .result {
  margin: 28px 0 0;
  font-size: 34px;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 18px;
}
.feedback .result::before { content: ""; width: 60px; height: 4px; background: var(--dim); }
.feedback .result.good { color: var(--volt); }
.feedback .result.good::before { background: var(--volt); }
.feedback .foot { bottom: 160px; }

/* ---------- 10 No magic words ---------- */
.magic .egs {
  margin: 24px 0 0;
  font-size: 24px;
  color: var(--dim);
  letter-spacing: 0.02em;
}
.magic .stops { margin: 36px 0 0; padding: 0; list-style: none; }
.magic .stops li {
  position: relative;
  display: table;
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
  padding: 16px 0;
  margin-bottom: 8px;
}
.magic .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;
}
.magic .stops li.dead { color: var(--dim); }

/* ---------- 11 Now use it on your real work ---------- */
.work .two {
  display: grid;
  grid-template-columns: 620px 1fr;
  gap: 80px;
  margin-top: 48px;
}
.work .steps { list-style: none; margin: 0; padding: 0; }
.work .steps li {
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: 20px;
  padding: 26px 0;
  border-bottom: 2px solid var(--line);
}
.work .steps li:last-child { border-bottom: 0; }
.work .steps li b {
  font-family: var(--display);
  font-weight: 300;
  font-size: 52px;
  line-height: 1;
  color: var(--volt);
}
.work .steps h3 { font-size: 34px; font-weight: 800; letter-spacing: -0.02em; margin: 0 0 8px; line-height: 1.1; }
.work .steps p { font-size: 23px; color: var(--muted); margin: 0; line-height: 1.4; }
.work .prompts { display: flex; flex-direction: column; gap: 28px; }
.work .prompt.small pre { font-size: 23px; line-height: 1.45; }

/* ---------- 12 Catch it being wrong ---------- */
.catch .sub { margin-top: 24px; }
.catch .prompt { margin-top: 36px; max-width: 1200px; }
.catch .docmock {
  position: absolute;
  right: 120px;
  top: 300px;
  width: 440px;
}
.catch .docmock .page {
  background: var(--surface);
  border: 2px solid var(--line);
  padding: 30px 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.catch .docmock .page i { display: block; height: 16px; background: var(--surface-2); border-radius: 3px; }
.catch .docmock .page i.hot { background: var(--volt); outline: 6px solid rgba(255, 225, 0, 0.18); }
.catch .docmock .tag {
  margin-top: 20px;
  background: var(--volt);
  color: var(--volt-ink);
  font-size: 22px;
  font-weight: 600;
  line-height: 1.35;
  padding: 18px 22px;
  position: relative;
}
.catch .docmock .tag::before {
  content: "";
  position: absolute;
  left: 40px;
  top: -14px;
  border: 7px solid transparent;
  border-bottom-color: var(--volt);
  border-top: 0;
}
.catch .foot { bottom: 110px; }

/* ---------- 13 Ship + next Monday ---------- */
.ship .big { font-size: 72px; max-width: 1500px; }
.ship .sub { margin-top: 32px; }
.ship .nextblock {
  position: absolute;
  left: 120px;
  right: 120px;
  bottom: 200px;
  border-top: 2px solid var(--line);
  padding-top: 36px;
}
.ship .nextblock small {
  display: block;
  font-family: var(--display);
  font-weight: 300;
  font-size: 20px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--volt);
  margin-bottom: 14px;
}
.ship .nextblock .display { font-size: 96px; }
.ship .nextblock .sub { margin-top: 14px; font-size: 30px; }

/* ---------- 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; }
#notes code { font-family: var(--mono); color: var(--muted); }
#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 .pn code { font-family: var(--mono); color: var(--muted); }
#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; }
}