/* Universal research-paper slide deck — minimal text, visual-first */

:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --text: #f0f2f8;
  --muted: #8b92a8;
  --accent: #6c8cff;
  --accent2: #56d4a0;
  --warn: #ffb347;
  --gap: #ff6b8a;
  font-family: "Inter", "Segoe UI", system-ui, sans-serif;
}

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

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

.deck {
  height: 100vh;
  width: 100vw;
  position: relative;
}

.slide {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 3rem 4rem;
  opacity: 0;
  transition: opacity 0.35s ease;
}

.slide.active {
  display: flex;
  opacity: 1;
}

.slide-tag {
  position: absolute;
  top: 1.5rem;
  left: 2rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.slide-num {
  position: absolute;
  bottom: 1.5rem;
  right: 2rem;
  font-size: 0.85rem;
  color: var(--muted);
}

/* ── Slide types ── */

.slide-cover h1 {
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 700;
  text-align: center;
  max-width: 18ch;
  line-height: 1.15;
}

.slide-cover .authors {
  margin-top: 1.5rem;
  color: var(--muted);
  font-size: 1.1rem;
}

.slide-cover .meta {
  margin-top: 0.5rem;
  color: var(--accent);
  font-size: 0.95rem;
}

.slide-hook .visual {
  display: flex;
  gap: 3rem;
  align-items: center;
  margin-bottom: 2rem;
}

.icon-circle {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  background: var(--surface);
  border: 2px solid var(--gap);
}

.icon-circle.good { border-color: var(--accent2); }

.slide-hook h2,
.slide-idea h2,
.slide-close h2 {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  text-align: center;
  max-width: 22ch;
  line-height: 1.25;
}

.slide-hook p,
.slide-idea p.sub {
  margin-top: 1rem;
  color: var(--muted);
  font-size: 1.1rem;
  text-align: center;
  max-width: 36ch;
}

/* Before / After split */
.split {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 2rem;
  align-items: center;
  width: min(900px, 90vw);
}

.panel {
  background: var(--surface);
  border-radius: 16px;
  padding: 2rem;
  min-height: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.panel.before { border: 2px dashed var(--gap); }
.panel.after  { border: 2px solid var(--accent2); }

.panel .label {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  color: var(--muted);
}

.panel svg { margin-bottom: 1rem; }

.panel p { font-size: 1rem; max-width: 20ch; }

.arrow-mid {
  font-size: 2rem;
  color: var(--accent);
}

/* Big idea slide */
.slide-idea .big-idea {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 600;
  text-align: center;
  max-width: 16ch;
  line-height: 1.2;
  color: var(--accent2);
}

/* Flow diagram */
.flow {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  justify-content: center;
  margin: 2rem 0;
}

.flow-node {
  background: var(--surface);
  border: 2px solid var(--accent);
  border-radius: 12px;
  padding: 1rem 1.25rem;
  font-size: 0.95rem;
  min-width: 100px;
  text-align: center;
}

.flow-arrow {
  color: var(--muted);
  font-size: 1.5rem;
}

/* Architecture diagram area */
.diagram-box {
  background: var(--surface);
  border-radius: 20px;
  padding: 2rem 3rem;
  margin: 1.5rem 0;
  max-width: 800px;
}

.diagram-box svg {
  display: block;
  margin: 0 auto;
}

.caption {
  margin-top: 1rem;
  color: var(--muted);
  font-size: 0.95rem;
  text-align: center;
  max-width: 40ch;
}

/* Stat cards */
.stats {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  justify-content: center;
  margin: 2rem 0;
}

.stat-card {
  background: var(--surface);
  border-radius: 16px;
  padding: 1.5rem 2rem;
  text-align: center;
  min-width: 160px;
  border-top: 4px solid var(--accent);
}

.stat-card .value {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent2);
}

.stat-card .label {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--muted);
}

/* Mini bar chart (CSS only) */
.bar-chart {
  display: flex;
  align-items: flex-end;
  gap: 1rem;
  height: 180px;
  margin: 1.5rem 0;
}

.bar-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.bar {
  width: 48px;
  border-radius: 6px 6px 0 0;
  background: linear-gradient(to top, var(--accent), #9aaeff);
}

.bar.highlight {
  background: linear-gradient(to top, var(--accent2), #8eecc4);
}

.bar-col span {
  font-size: 0.75rem;
  color: var(--muted);
}

/* Impact icons row */
.impact-row {
  display: flex;
  gap: 2.5rem;
  margin: 2rem 0;
  flex-wrap: wrap;
  justify-content: center;
}

.impact-item {
  text-align: center;
  max-width: 140px;
}

.impact-item .emoji {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
}

.impact-item p {
  font-size: 0.9rem;
  color: var(--muted);
}

/* Close / takeaway */
.slide-close .takeaway {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  text-align: center;
  max-width: 20ch;
  line-height: 1.3;
  border-left: 4px solid var(--accent2);
  padding-left: 1.5rem;
}

/* Nav hint */
.nav-hint {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.75rem;
  color: var(--muted);
  opacity: 0.6;
}