:root {
  --canvas: #ececea;
  --paper: #fbfbf9;
  --surface: #f1f1ee;
  --surface-strong: #e8e8e4;
  --ink: #121212;
  --muted: #60646a;
  --line: #d8d8d3;
  --red: #e53225;
  --red-soft: #fde7e3;
  --white: #ffffff;
  --font: "Inter", "Helvetica Neue", "Segoe UI", Roboto, system-ui, -apple-system, Arial, sans-serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  /* Type scale: one token per semantic role */
  --type-cover: 108px;
  --type-section: 100px;
  --type-title: 76px;
  --type-lead: 36px;
  --type-body: 28px;
  --type-box-title: 28px;
  --type-box-body: 23px;
  --type-note: 20px;
  --type-meta: 17px;
  --type-label: 16px;
  --type-metric: 56px;
  --type-section-number: 220px;
  --type-step: 54px;
  --type-process: 34px;
  --type-icon: 66px;
  --type-index: 39px;

  /* Spacing scale */
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
  --box-gap: var(--space-3);

  --radius: 24px;
  --radius-sm: 14px;
  --shadow: 0 22px 60px rgba(18, 18, 18, .10);
}

* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; overflow: hidden; }
body {
  background: var(--canvas);
  color: var(--ink);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration-color: rgba(229,50,37,.55); text-decoration-thickness: 2px; text-underline-offset: .18em; }
button { font: inherit; }

.deck {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
}

.slide {
  position: absolute;
  width: 1920px;
  height: 1080px;
  padding: 64px 92px 48px;
  overflow: hidden;
  color: var(--ink);
  background: var(--paper);
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: scale(var(--deck-scale, 1));
  transform-origin: center;
}
.slide.active { opacity: 1; pointer-events: auto; }

.slide-grid {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}
.slide-grid::before {
  content: "";
  position: absolute;
  width: 520px;
  height: 520px;
  right: -310px;
  top: -310px;
  border: 86px solid rgba(229,50,37,.06);
  border-radius: 50%;
}
.slide-grid::after {
  content: "";
  position: absolute;
  width: 200px;
  height: 4px;
  left: 92px;
  bottom: 46px;
  border-radius: 99px;
  background: var(--red);
  opacity: .9;
}

.slide-head, .slide-body, .slide-foot { position: relative; z-index: 1; }
.slide-head {
  height: 52px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  margin: 0;
  padding: 9px 14px 8px;
  border-radius: 999px;
  color: var(--red);
  background: var(--red-soft);
  font: 750 var(--type-label)/1 var(--font);
  letter-spacing: .09em;
  text-transform: uppercase;
}
.slide-number {
  margin: 8px 0 0;
  color: var(--muted);
  font: 700 var(--type-meta)/1 var(--font);
  letter-spacing: .04em;
  text-transform: lowercase;
}
.slide-body {
  height: 900px;
  padding: 36px 0 24px;
}
.slide-foot {
  height: 24px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  padding-left: 230px;
  padding-right: 110px;
  color: #777a7e;
  font: 650 14px/1 var(--font);
  letter-spacing: .06em;
  text-transform: uppercase;
}
.section-name { color: var(--red); }

h1, h2, h3, p { margin-top: 0; }
h1, h2 {
  max-width: 1620px;
  margin-bottom: 32px;
  color: var(--ink);
  font-family: var(--font);
  font-weight: 850;
  letter-spacing: -.045em;
  text-wrap: balance;
}
h1 { font-size: var(--type-cover); line-height: .94; }
h2 { font-size: var(--type-title); line-height: 1.01; }
h3 { font-size: var(--type-box-title); line-height: 1.12; }
p, li { font-size: var(--type-body); line-height: 1.37; }
p.lead { max-width: 1520px; font-size: var(--type-lead); line-height: 1.27; color: var(--muted); letter-spacing: -.018em; }
strong { color: var(--ink); }
.accent { color: var(--red); }
.muted { color: var(--muted); }
.mono { font-family: var(--mono); }
.small { font-size: var(--type-note); line-height: 1.35; }
.micro { font-size: var(--type-meta); line-height: 1.35; }
.rule { width: 108px; height: 7px; margin: 0 0 30px; border-radius: 99px; background: var(--red); }

/* Opening and section slides */
.cover { background: var(--white); }
.cover .slide-grid::before {
  width: 760px;
  height: 760px;
  right: -420px;
  top: -420px;
  border-width: 118px;
  border-color: rgba(229,50,37,.085);
}
.cover .slide-body {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(440px, .55fr);
  gap: 96px;
  align-items: center;
}
.cover .title-block { align-self: center; }
.cover-logo {
  display: block;
  width: 118px;
  height: 118px;
  margin: 0 0 26px;
  object-fit: contain;
}
.cover h1 { max-width: 1220px; font-size: var(--type-cover); }
.cover .subtitle { max-width: 1160px; font-size: var(--type-lead); line-height: 1.34; color: var(--muted); }
.event-block {
  align-self: center;
  padding: 42px 46px;
  border-radius: 30px;
  background: #171717;
  color: var(--white);
}
.event-block .date { margin-bottom: 0; color: #ff8c82; font: 750 var(--type-note)/1.3 var(--font); letter-spacing: .04em; text-transform: uppercase; }
.speakers { display: grid; gap: 28px; margin-top: 42px; }
.speaker { padding-top: 22px; border-top: 1px solid rgba(255,255,255,.18); }
.speaker b { display: block; color: var(--white); font: 800 var(--type-box-title)/1.1 var(--font); letter-spacing: -.025em; }
.speaker span, .speaker a { display: block; margin-top: 8px; color: #d2d2ce; font-size: var(--type-meta); line-height: 1.35; }

.section-slide { background: #f4f4f1; }
.section-slide .slide-grid::before {
  width: 700px;
  height: 700px;
  right: -280px;
  top: -300px;
  border-width: 104px;
  border-color: rgba(229,50,37,.10);
}
.section-slide .slide-body {
  display: grid;
  grid-template-columns: 350px 1fr;
  gap: 86px;
  align-items: center;
}
.section-number { color: var(--red); font: 900 var(--type-section-number)/.74 var(--font); letter-spacing: -.09em; }
.section-slide h2 { max-width: 1280px; font-size: var(--type-section); }
.section-slide .lead { color: var(--muted); }

/* Core layouts */
.two-col { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--box-gap); align-items: start; }
.three-col { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--box-gap); }
.four-col { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--box-gap); }
.cards { display: grid; gap: var(--box-gap); }
.card {
  padding: 32px 34px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  background: var(--surface);
}
.card.accent-card { background: var(--surface); border-color: transparent; }
.card h3 { margin: 0 0 var(--space-2); font-family: var(--font); font-size: var(--type-box-title); font-weight: 800; letter-spacing: -.015em; text-transform: none; }
.card p, .card li { margin-bottom: 0; font-size: var(--type-box-body); line-height: 1.34; }
.card ul { margin: 12px 0 0; padding-left: 25px; }
.step-number { display: block; margin-bottom: var(--space-3); color: var(--red); font: 900 var(--type-step)/1 var(--font); letter-spacing: -.05em; }

.agenda .card { min-height: 400px; }
.agenda .card h3 { font-size: var(--type-box-title); letter-spacing: -.015em; text-transform: none; }
.agenda .card p { font-size: var(--type-box-body); }

.quote {
  max-width: 1510px;
  padding: 34px 40px;
  border-radius: var(--radius);
  background: var(--red-soft);
  color: var(--ink);
}
.quote p { margin: 0; color: var(--ink); font: 750 var(--type-lead)/1.24 var(--font); letter-spacing: -.025em; }
.quote cite { display: block; margin-top: var(--space-2); color: var(--muted); font: 600 var(--type-meta)/1.4 var(--font); }

/* Horizontal synthesis boxes placed immediately after card/box groups */
.agenda-thesis,
.three-col + .lead,
.pipeline + .small,
.model-table + .lead,
.two-col + .small,
.metrics + p,
.architecture + .small,
.loop-grid + .small,
.four-col + .lead,
.two-col + .quote,
.three-col + .quote {
  display: block;
  width: 100%;
  max-width: none;
  margin-top: var(--box-gap) !important;
  margin-bottom: 0;
  padding: 22px 26px;
  border: 1px solid rgba(229,50,37,.10);
  border-radius: 18px;
  background: var(--red-soft);
  color: var(--ink);
  font-family: var(--font);
  font-size: var(--type-box-body) !important;
  font-weight: 500;
  line-height: 1.34;
  letter-spacing: 0;
}
.two-col + .quote p,
.three-col + .quote p {
  color: var(--ink);
  font: 500 var(--type-box-body)/1.34 var(--font);
  letter-spacing: 0;
}

.timeline { position: relative; display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; margin-top: 66px; }
.timeline::before { content: ""; position: absolute; top: 24px; left: 4%; right: 4%; height: 3px; background: var(--line); }
.milestone { position: relative; padding: 66px 28px 0 0; }
.milestone::before { content: ""; position: absolute; top: 8px; width: 34px; height: 34px; border: 8px solid var(--paper); border-radius: 50%; background: var(--red); box-shadow: 0 0 0 2px var(--red); }
.milestone time { display: block; color: var(--red); font: 850 24px/1 var(--font); }
.milestone h3 { margin: 14px 0 10px; font: 800 var(--type-box-title)/1.1 var(--font); letter-spacing: -.015em; }
.milestone p { max-width: 350px; font-size: var(--type-note); color: var(--muted); }

.pipeline { display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--box-gap); counter-reset: stage; }
.pipeline .card { position: relative; min-height: 350px; padding-top: 82px; }
.pipeline .card::before { counter-increment: stage; content: "0" counter(stage); position: absolute; top: 25px; left: 32px; color: var(--red); font: 850 var(--type-process)/1 var(--font); }
.pipeline .card:not(:last-child)::after { content: "→"; position: absolute; z-index: 3; top: 45%; right: -31px; width: 38px; height: 38px; display: grid; place-items: center; border-radius: 50%; color: var(--white); background: var(--red); font-size: var(--type-note); }

.architecture { display: grid; grid-template-columns: 1fr 130px 1.08fr; align-items: center; gap: var(--box-gap); }
.arch-box { min-height: 410px; padding: 40px; border: 0; border-radius: var(--radius); background: var(--surface); }
.arch-box.core { color: var(--ink); background: var(--surface); box-shadow: inset 0 0 0 2px var(--red); }
.arch-box.core h3, .arch-box.core strong { color: var(--ink); }
.arch-box.core p { color: var(--ink); }
.arch-box h3 { margin-bottom: var(--space-2); font: 800 var(--type-box-title)/1.1 var(--font); letter-spacing: -.015em; }
.arch-box p { font-size: var(--type-box-body); }
.arch-arrow { color: var(--red); font: 850 var(--type-icon)/1 var(--font); text-align: center; }
.pills { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.pill { padding: 10px 15px; border: 0; border-radius: 999px; background: var(--white); font: 650 17px/1 var(--mono); }
.arch-box.core .pill { color: var(--ink); background: var(--white); }

.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--box-gap); margin: var(--space-4) 0 0; }
.metric { padding: 30px; border-radius: var(--radius); background: var(--surface); }
.metric b { display: block; color: var(--red); font: 900 var(--type-metric)/1 var(--font); letter-spacing: -.05em; }
.metric span { display: block; margin-top: var(--space-1); color: var(--muted); font: 700 var(--type-meta)/1.3 var(--font); letter-spacing: .04em; text-transform: uppercase; }

.model-table { width: 100%; overflow: hidden; border-collapse: separate; border-spacing: 0; border-radius: var(--radius); background: var(--surface); }
.model-table th, .model-table td { padding: 22px 26px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; font-size: var(--type-box-body); line-height: 1.25; }
.model-table th { color: var(--white); background: #171717; font: 750 var(--type-label)/1 var(--font); letter-spacing: .06em; text-transform: uppercase; }
.model-table td:first-child { width: 88px; color: var(--red); font: 900 var(--type-index)/1 var(--font); }
.model-table tbody tr:last-child td { border-bottom: 0; }

.figure-layout { display: grid; grid-template-columns: 1.36fr .64fr; gap: var(--space-5); align-items: center; }
.figure-frame { display: grid; place-items: center; min-height: 590px; padding: 22px; overflow: hidden; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
.figure-frame img { display: block; max-width: 100%; max-height: 595px; object-fit: contain; }
.figure-notes { display: grid; gap: var(--box-gap); }
.finding { padding: 24px 26px; border-radius: 20px; background: var(--surface); }
.finding:first-child { background: var(--surface); }
.finding b { display: block; margin-bottom: var(--space-1); color: var(--red); font: 800 var(--type-label)/1.2 var(--font); letter-spacing: .045em; text-transform: uppercase; }
.finding p { margin: 0; font-size: var(--type-box-body); }

.loop-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--box-gap); }
.loop { min-height: 490px; padding: 36px; border: 1px solid transparent; border-radius: var(--radius); background: var(--surface); }
.loop.on { border-color: var(--red); background: var(--surface); box-shadow: inset 0 0 0 2px var(--red); }
.loop .label { color: var(--red); font: 750 var(--type-label)/1 var(--font); letter-spacing: .07em; text-transform: uppercase; }
.loop h3 { margin: var(--space-2) 0 var(--space-2); font: 850 var(--type-box-title)/1 var(--font); letter-spacing: -.015em; }
.loop p { font-size: var(--type-box-body); }
.tradeoff { margin-top: var(--space-3); padding-top: var(--space-2); border-top: 1px solid var(--line); color: var(--muted); font: 650 var(--type-note)/1.4 var(--font); }

/* Closing */
.closing { background: var(--white); }
.closing h2 { font-size: var(--type-cover); }
.closing .lead { color: var(--muted) !important; }
.links { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--box-gap); margin-top: var(--space-4); }
.link-row { display: grid; grid-template-columns: 170px 1fr; gap: var(--space-3); padding: 20px 22px; border-radius: 16px; background: var(--surface); }
.link-row b { color: var(--red); font: 800 var(--type-label)/1.4 var(--font); letter-spacing: .05em; text-transform: uppercase; }
.link-row a, .link-row span { color: var(--ink); font-size: var(--type-note); line-height: 1.32; overflow-wrap: anywhere; }

/* Controls: the only visible slide count */
.deck-nav {
  position: fixed;
  z-index: 20;
  right: 22px;
  bottom: 20px;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px;
  border: 0;
  border-radius: 999px;
  color: var(--white);
  background: rgba(18,18,18,.93);
  box-shadow: 0 10px 30px rgba(0,0,0,.18);
  backdrop-filter: blur(10px);
}
.deck-nav button { width: 44px; height: 44px; border: 0; border-radius: 50%; color: var(--white); background: transparent; cursor: pointer; }
.deck-nav button:hover, .deck-nav button:focus-visible { background: var(--red); outline: none; }
.deck-nav button:disabled { opacity: .28; cursor: default; }

.progress { position: fixed; z-index: 19; left: 0; right: 0; bottom: 0; height: 4px; background: rgba(18,18,18,.10); }
.progress span { display: block; width: 0; height: 100%; background: var(--red); transition: width .18s ease; }

.overview { position: fixed; z-index: 30; inset: 0; overflow: auto; padding: 52px; color: var(--ink); background: rgba(246,246,243,.98); }
.overview[hidden] { display: none; }
.overview-item { width: calc(25% - 18px); min-height: 130px; margin: 8px; padding: 22px; border: 1px solid var(--line); border-radius: 18px; color: var(--ink); background: var(--white); text-align: left; vertical-align: top; cursor: pointer; }
.overview-item:hover, .overview-item:focus-visible { border-color: var(--red); outline: 3px solid rgba(229,50,37,.22); }
.overview-item span { display: block; margin-bottom: 12px; color: var(--red); font: 800 15px/1 var(--font); }
.overview-item b { font: 800 21px/1.18 var(--font); letter-spacing: -.02em; }

@media (prefers-reduced-motion: reduce) { .progress span { transition: none; } }

@media print {
  @page { size: 16in 9in; margin: 0; }
  html, body { width: auto; height: auto; overflow: visible; background: white; }
  .deck { position: static; display: block; }
  .slide { position: relative; display: block; opacity: 1; pointer-events: auto; transform: none; zoom: .8; box-shadow: none; page-break-after: always; break-after: page; }
  .deck-nav, .progress, .overview { display: none !important; }
}