:root {
  color-scheme: light;
  --bg: #f8f6ef;
  --text: #172026;
  --muted: #5d6670;
  --accent: #0f766e;
  --accent-2: #f59e0b;
  --line: #d9d6cc;
  --paper: #fffefa;
  --dark: #10262a;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body.presentation-body { margin: 0; background: var(--bg); color: var(--text); font-family: "Atkinson Hyperlegible", "Segoe UI", system-ui, sans-serif; line-height: 1.45; }
.presentation-shell { min-height: 100vh; display: grid; grid-template-rows: auto 1fr auto; }
.presentation-topbar, .presentation-footer { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1rem 1.4rem; color: var(--muted); font-size: .95rem; }
.presentation-topbar a { color: var(--accent); font-weight: 800; text-decoration: none; }
.slide-counter { font-variant-numeric: tabular-nums; }
.deck { position: relative; min-height: 0; }
.slide { display: none; min-height: calc(100vh - 8rem); padding: clamp(2rem, 5vw, 5rem); place-items: center; overflow: hidden; }
.slide.is-active { display: grid; }
.slide-content { width: min(1120px, 100%); }
.slide-kicker { margin: 0 0 1rem; color: var(--accent); font-size: clamp(1rem, 1.8vw, 1.35rem); font-weight: 850; letter-spacing: .04em; text-transform: uppercase; }
.slide h1, .slide h2 { max-width: 17ch; margin: 0; font-weight: 880; line-height: 1.04; letter-spacing: -.035em; text-wrap: balance; }
.slide h1 { font-size: clamp(3.4rem, 8vw, 7rem); }
.slide h2 { font-size: clamp(2.5rem, 5.2vw, 5rem); }
.slide p, .slide li { max-width: 66ch; font-size: clamp(1.35rem, 2.15vw, 2.05rem); }
.slide p { margin: 1.35rem 0 0; }
.slide ul, .slide ol { display: grid; gap: .85rem; margin: 1.7rem 0 0; padding-left: 1.35em; }
.title-slide::after { content: "</>"; position: fixed; right: 5vw; bottom: 10vh; color: rgba(15,118,110,.12); font: 900 clamp(6rem, 18vw, 16rem)/1 monospace; z-index: -1; }
.fragment { opacity: 0; transform: translateY(10px); transition: opacity 180ms ease, transform 180ms ease; }
.fragment.is-visible { opacity: 1; transform: translateY(0); }
.fragment.is-dimmed { opacity: .48; }
.formula, .flow { display: flex; flex-wrap: wrap; align-items: center; gap: 1rem; margin-top: 2.3rem; }
.formula span, .flow span { border: 2px solid var(--text); border-radius: 12px; background: var(--paper); padding: 1rem 1.2rem; }
.formula strong, .formula small { display: block; }
.formula strong { font-size: clamp(1.4rem, 2vw, 2rem); }
.formula small { margin-top: .25rem; color: var(--muted); font-size: 1rem; }
.formula b, .flow b { color: var(--accent); font-size: 2rem; }
.comparison { width: 100%; margin-top: 2rem; border-collapse: collapse; background: var(--paper); font-size: clamp(1rem, 1.5vw, 1.35rem); }
.comparison th, .comparison td { padding: .9rem 1rem; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.comparison th { color: var(--accent); }
.split { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); align-items: center; gap: clamp(2rem, 6vw, 6rem); }
.split > *, .engine-detail > * { min-width: 0; }
.split h2 { max-width: 100%; font-size: clamp(2.3rem, 4.4vw, 4.4rem); overflow-wrap: anywhere; }
.stack { display: grid; gap: 1rem; }
.stack p { margin: 0; padding-left: 1rem; border-left: 4px solid var(--accent-2); }
.stack span { color: var(--muted); }
.dark-slide { background: var(--dark); color: #f8fafc; }
.dark-slide .slide-kicker { color: #5eead4; }
.dark-slide .flow span { border-color: #5eead4; background: rgba(255,255,255,.06); }
.dark-slide .flow b { color: #fbbf24; }
.problem-solution { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.2rem; margin-top: 2rem; }
.problem-solution > div { border-top: 5px solid var(--accent); padding: 1.1rem 0; }
.problem-solution strong { font-size: clamp(1.3rem, 2vw, 1.8rem); }
.problem-solution p { font-size: clamp(1.15rem, 1.7vw, 1.5rem); }
.source-note { color: var(--muted); font-size: .95rem !important; }
.source-note a { color: var(--accent); font-weight: 750; }
.example-link { justify-self: start; color: var(--accent); font-size: 1.2rem; font-weight: 850; }
.steps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1rem; margin-top: 2rem; }
.steps div { border-top: 4px solid var(--accent); padding-top: 1rem; }
.steps span, .steps strong, .steps small { display: block; }
.steps span { color: var(--accent); font-size: 2rem; font-weight: 900; }
.steps strong { font-size: 1.25rem; }
.steps small { margin-top: .25rem; color: var(--muted); font-size: 1rem; }
.idea-list strong { color: var(--accent); }
.engine-detail { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); align-items: center; gap: clamp(2rem, 5vw, 5rem); }
.engine-detail h2 { max-width: 13ch; font-size: clamp(2.4rem, 4.6vw, 4.5rem); }
.hardware { padding-left: 1rem; border-left: 4px solid var(--accent-2); color: var(--muted); font-size: clamp(1.05rem, 1.55vw, 1.4rem) !important; }
.pros-cons { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.2rem; }
.pros-cons > div { border-top: 5px solid var(--accent); padding-top: .9rem; }
.pros-cons > div:last-child { border-color: var(--accent-2); }
.pros-cons strong { font-size: clamp(1.2rem, 1.8vw, 1.6rem); }
.pros-cons ul { gap: .45rem; margin-top: .65rem; }
.pros-cons li { font-size: clamp(1rem, 1.4vw, 1.25rem); }
.accent-slide { background: #dff7f2; }
.brief { width: min(800px, 100%); margin-top: 2rem; padding: 1.2rem 1.5rem; border-left: 6px solid var(--accent); background: var(--paper); }
.brief p { margin: .6rem 0; }
.presentation-footer nav { display: flex; gap: .5rem; }
.presentation-footer button { width: 2.5rem; height: 2.5rem; border: 1px solid var(--line); border-radius: 50%; background: var(--paper); color: var(--text); cursor: pointer; font: 800 1.2rem/1 system-ui; }
.presentation-footer button:hover, .presentation-footer button:focus-visible { border-color: var(--accent); outline: 3px solid rgba(15,118,110,.18); }

@media (max-width: 760px) {
  .slide { min-height: calc(100vh - 9rem); padding: 1.5rem; }
  .slide p, .slide li { font-size: clamp(1.1rem, 4.2vw, 1.5rem); }
  .split, .engine-detail, .problem-solution, .steps { grid-template-columns: 1fr; }
  .pros-cons { grid-template-columns: 1fr 1fr; }
  .steps { gap: .55rem; }
  .steps div { display: grid; grid-template-columns: 2rem 1fr; gap: 0 .5rem; padding-top: .4rem; }
  .steps small { grid-column: 2; }
  .presentation-topbar, .presentation-footer { padding: .75rem 1rem; }
  .comparison { font-size: .9rem; }
  .comparison th, .comparison td { padding: .55rem; }
}

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