@import url('https://fonts.googleapis.com/css2?family=Libre+Baskerville:wght@400;700&family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:      #1a120c;
  --surface: #2a1f17;
  --surf2:   #3d2b1f;
  --border:  #3d2b1f;
  --text:    #ede4d5;
  --muted:   #8b7560;
  --accent:  #e06b55;
  --green:   #3d9e82;
  --sand:    #c4a67d;
}

html, body {
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: 'IBM Plex Sans', sans-serif;
}

/* ── Slide layout ── */
.slide {
  position: relative;
  width: 100vw;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 64px 80px 100px;
  animation: fadein 0.38s ease;
}

@keyframes fadein {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.slide.overflow-hidden { overflow: hidden; }

/* Top bar accent */
.slide.bar-accent::before,
.slide.bar-green::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
}
.slide.bar-accent::before { background: var(--accent); }
.slide.bar-green::before  { background: var(--green); }

/* ── Typography ── */
.tag {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
  position: relative;
  z-index: 1;
}
.tag.tg { color: var(--green); }

h1 {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(40px, 6vw, 80px);
  font-weight: 700;
  line-height: 1.1;
  text-align: center;
  position: relative;
  z-index: 1;
}

h2 {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(26px, 4vw, 54px);
  font-weight: 700;
  line-height: 1.15;
  text-align: center;
  position: relative;
  z-index: 1;
}

.sub {
  font-size: clamp(15px, 1.8vw, 20px);
  color: var(--muted);
  text-align: center;
  margin-top: 20px;
  line-height: 1.55;
  position: relative;
  z-index: 1;
}

.big-quote {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(22px, 3.8vw, 50px);
  line-height: 1.28;
  text-align: center;
  max-width: 820px;
}

/* ── Ghost number (section headers) ── */
.ghost {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(140px, 28vw, 280px);
  font-weight: 700;
  color: var(--surf2);
  position: absolute;
  line-height: 1;
  pointer-events: none;
  user-select: none;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -52%);
  z-index: 0;
}

/* ── Terminal widget ── */
.terminal {
  background: #0f0a06;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px 24px;
  width: 100%;
  max-width: 700px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 14px;
  line-height: 1.8;
}

.t-bar { display: flex; gap: 7px; margin-bottom: 16px; }
.t-dot { width: 11px; height: 11px; border-radius: 50%; }
.td-r  { background: #ff5f56; }
.td-y  { background: #ffbd2e; }
.td-g  { background: #27c93f; }

.t-prompt { color: var(--green); font-size: 12px; margin-bottom: 6px; }
.t-cmd    { color: var(--text); }
.t-out    { color: var(--muted); margin-top: 12px; font-size: 12px; line-height: 1.7; }

/* Prompt colour highlights: who / task / how */
.hw { color: var(--green);  }
.ht { color: var(--accent); }
.hh { color: var(--sand);   }

/* ── Prompt legend ── */
.legend {
  display: flex;
  gap: 28px;
  margin-top: 20px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--muted);
}

/* ── Demo cards (slide 4) ── */
.demo-cards {
  display: flex;
  gap: 24px;
  width: 100%;
  max-width: 800px;
}
.demo-card {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 36px 32px;
  text-align: center;
}
.demo-card .n {
  font-family: 'Libre Baskerville', serif;
  font-size: 58px;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 12px;
}
.demo-card .t {
  font-family: 'Libre Baskerville', serif;
  font-size: 22px;
  margin-bottom: 10px;
}
.demo-card .d { color: var(--muted); font-size: 14px; line-height: 1.6; }

/* ── Two-column mental model (slide 3) ── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  max-width: 720px;
  width: 100%;
}
.col-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 28px;
}
.col-box.good { border-color: var(--green); }
.col-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 14px;
  color: var(--accent);
}
.col-box.good .col-label { color: var(--green); }
.col-cmd {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 14px;
  color: var(--text);
  margin-bottom: 14px;
  line-height: 1.7;
}
.col-result { font-size: 14px; color: var(--muted); line-height: 1.6; }
.col-box.good .col-result { color: var(--green); }

/* ── Callout (slide 8) ── */
.callout {
  background: var(--surface);
  border-left: 4px solid var(--green);
  border-radius: 0 8px 8px 0;
  padding: 36px 44px;
  max-width: 700px;
  width: 100%;
}
.callout .ct {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(18px, 2.5vw, 26px);
  line-height: 1.45;
}
.callout .cs {
  margin-top: 20px;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
}
.callout .cs code {
  font-family: 'IBM Plex Mono', monospace;
  color: var(--green);
  font-size: 13px;
}

/* ── VS comparison (slide 10) ── */
.vs-row {
  display: flex;
  gap: 52px;
  align-items: flex-start;
  margin-top: 32px;
}
.vs-side { text-align: center; }
.vs-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 10px;
}
.vs-label.bad  { color: var(--accent); }
.vs-label.good { color: var(--green); }
.vs-text { font-size: 16px; color: var(--muted); line-height: 1.5; }
.vs-div  { color: var(--surf2); font-size: 28px; padding-top: 8px; }

/* ── Formula boxes (slide 12) ── */
.formula {
  display: flex;
  max-width: 860px;
  width: 100%;
}
.fbox {
  flex: 1;
  padding: 36px 28px;
  text-align: center;
  border: 1px solid;
}
.fbox:first-child { border-radius: 8px 0 0 8px; }
.fbox:last-child  { border-radius: 0 8px 8px 0; }
.fbox .fk {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.fbox .fw {
  font-family: 'Libre Baskerville', serif;
  font-size: 30px;
  font-weight: 700;
  margin-bottom: 14px;
}
.fbox .fd { color: var(--muted); font-size: 14px; line-height: 1.55; }

.fbox.f1 { background: rgba(61,158,130,0.10); border-color: var(--green);  }
.fbox.f1 .fk, .fbox.f1 .fw { color: var(--green);  }
.fbox.f2 { background: rgba(224,107,85,0.10);  border-color: var(--accent); }
.fbox.f2 .fk, .fbox.f2 .fw { color: var(--accent); }
.fbox.f3 { background: rgba(196,166,125,0.10); border-color: var(--sand);   }
.fbox.f3 .fk, .fbox.f3 .fw { color: var(--sand);   }

/* ── Navigation bar ── */
.deck-nav {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 16px;
  z-index: 100;
  background: rgba(26, 18, 12, 0.88);
  backdrop-filter: blur(10px);
  padding: 8px 18px;
  border-radius: 40px;
  border: 1px solid var(--border);
}
.nav-btn {
  background: none;
  border: none;
  color: var(--muted);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 16px;
  text-decoration: none;
  transition: color 0.18s;
  cursor: pointer;
}
.nav-btn:hover { color: var(--text); }
.nav-btn.disabled { opacity: 0.25; pointer-events: none; }

.slide-info { display: flex; align-items: center; gap: 12px; }
.dots { display: flex; gap: 5px; align-items: center; }
.dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--surf2);
  transition: background 0.22s, transform 0.22s;
}
.dot.on { background: var(--accent); transform: scale(1.5); }

.slide-num {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--muted);
  min-width: 44px;
  text-align: center;
}

/* ── Resource links ── */
.resources {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  max-width: 700px;
  width: 100%;
}
.res-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 6px 14px;
  transition: color 0.18s, border-color 0.18s;
}
.res-link:hover { color: var(--text); border-color: var(--muted); }
.res-link .res-icon { font-size: 13px; }

/* ── Keyboard hint ── */
.key-hint {
  position: fixed;
  top: 20px;
  right: 24px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: var(--surf2);
  z-index: 100;
  pointer-events: none;
}