/* ============================================================
   PhD Spark — science-editorial design system
   ============================================================ */

:root {
  /* Light theme */
  --bg: #f6f7fb;
  --bg-2: #eef1f8;
  --surface: #ffffff;
  --surface-2: #f2f4fa;
  --text: #10131f;
  --muted: #56607a;
  --border: #e2e6f0;
  --accent: #e8890c;          /* spark amber */
  --accent-soft: #f5a623;
  --accent-text: #ffffff;
  --accent-2: #0e9bb5;        /* science cyan */
  --accent-3: #6d5ef0;        /* frontier violet */
  --radius: 14px;
  --radius-sm: 10px;
  --max-width: 1120px;
  --font-serif: "Newsreader", Georgia, "Times New Roman", serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color-scheme: light;
}

[data-theme="dark"] {
  --bg: #070a14;
  --bg-2: #0b0f1d;
  --surface: #101627;
  --surface-2: #161d33;
  --text: #eaf0fb;
  --muted: #97a6c4;
  --border: #212b45;
  --accent: #f5a623;
  --accent-soft: #ffbf47;
  --accent-text: #1a1200;
  --accent-2: #35d0e8;
  --accent-3: #9c8cff;
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #070a14;
    --bg-2: #0b0f1d;
    --surface: #101627;
    --surface-2: #161d33;
    --text: #eaf0fb;
    --muted: #97a6c4;
    --border: #212b45;
    --accent: #f5a623;
    --accent-soft: #ffbf47;
    --accent-text: #1a1200;
    --accent-2: #35d0e8;
    --accent-3: #9c8cff;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 28px;
}

a { color: var(--accent); }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
}

/* ---- Shared type ---- */
h1, h2, h3 { font-family: var(--font-serif); font-weight: 500; letter-spacing: -0.01em; }
h1 { line-height: 1.08; }
h2 { line-height: 1.15; }

.grad {
  background: linear-gradient(100deg, var(--accent-soft) 0%, var(--accent-2) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.kicker {
  font-family: var(--font-sans);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.74rem;
  font-weight: 600;
  color: var(--accent-2);
  margin: 0 0 14px;
}

.section-sub {
  color: var(--muted);
  font-size: 1.05rem;
  margin: 0 0 40px;
  max-width: 620px;
}

/* ---- Reveal on scroll ---- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s cubic-bezier(.16,1,.3,1), transform 0.8s cubic-bezier(.16,1,.3,1);
}
.reveal.in-view { opacity: 1; transform: none; }
.exposure-grid .reveal:nth-child(2),
.persona-grid .reveal:nth-child(2),
.roadmap-grid .reveal:nth-child(2),
.how-grid .reveal:nth-child(2) { transition-delay: 0.08s; }
.exposure-grid .reveal:nth-child(3),
.persona-grid .reveal:nth-child(3),
.roadmap-grid .reveal:nth-child(3),
.how-grid .reveal:nth-child(3) { transition-delay: 0.16s; }
.exposure-grid .reveal:nth-child(4),
.persona-grid .reveal:nth-child(4),
.roadmap-grid .reveal:nth-child(4) { transition-delay: 0.24s; }
.persona-grid .reveal:nth-child(5),
.roadmap-grid .reveal:nth-child(5) { transition-delay: 0.32s; }
.persona-grid .reveal:nth-child(6) { transition-delay: 0.40s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .logo-mark, .blob, .net-nodes circle, .net-lines line, .aspire-track { animation: none !important; }
}

/* ============================================================
   Header
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  backdrop-filter: saturate(1.4) blur(14px);
  -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, background 0.25s ease;
}
.site-header.scrolled {
  border-bottom-color: var(--border);
  background: color-mix(in srgb, var(--bg) 92%, transparent);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.logo {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.24rem;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -0.01em;
}
.logo-mark {
  color: var(--accent);
  display: inline-block;
  animation: spark-pulse 2.6s ease-in-out infinite;
}
.accent { color: var(--accent); }
.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}
.site-nav a {
  font-family: var(--font-sans);
  text-decoration: none;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s ease;
}
.site-nav a:hover { color: var(--text); }
.site-nav a.is-current { color: var(--accent-2); }

@keyframes spark-pulse {
  0%, 100% { transform: scale(1) rotate(0deg); opacity: 1; }
  50% { transform: scale(1.16) rotate(-6deg); opacity: 0.82; }
}

/* ---- Buttons ---- */
.btn {
  font-family: var(--font-sans);
  display: inline-block;
  padding: 13px 22px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.94rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.18s ease, box-shadow 0.18s ease, filter 0.18s ease;
}
.btn-sm { padding: 9px 16px; font-size: 0.86rem; }
.btn-primary {
  background: linear-gradient(180deg, var(--accent-soft), var(--accent));
  color: var(--accent-text);
  border: none;
  box-shadow: 0 6px 18px -8px var(--accent);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 26px -10px var(--accent);
  filter: brightness(1.04);
}
.btn:active { transform: translateY(0); }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  position: relative;
  overflow: hidden;
  padding: 120px 0 96px;
  background:
    radial-gradient(1100px 520px at 72% -8%, color-mix(in srgb, var(--accent-2) 16%, transparent), transparent 60%),
    radial-gradient(900px 480px at 10% 0%, color-mix(in srgb, var(--accent) 12%, transparent), transparent 55%),
    var(--bg);
}
.graph-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  opacity: 0.9;
}
.hero-fade {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(180deg, transparent 55%, var(--bg) 100%);
}
.hero-inner { position: relative; z-index: 2; max-width: 820px; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-sans);
  color: var(--muted);
  font-weight: 500;
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  padding: 7px 15px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: color-mix(in srgb, var(--surface) 60%, transparent);
  backdrop-filter: blur(6px);
  margin: 0 0 26px;
}
.eyebrow .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent-2) 70%, transparent);
  animation: live-ping 2s ease-out infinite;
}
@keyframes live-ping {
  0% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent-2) 55%, transparent); }
  70%, 100% { box-shadow: 0 0 0 8px transparent; }
}

.hero h1 {
  font-size: clamp(2.4rem, 5.6vw, 4.2rem);
  margin: 0 0 24px;
}
.hero-sub {
  font-size: clamp(1.05rem, 1.7vw, 1.28rem);
  color: var(--muted);
  max-width: 660px;
  margin: 0 0 36px;
  line-height: 1.62;
}
.hero-sub em { color: var(--text); font-style: italic; }

.hero-form, .cta-form {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  max-width: 660px;
}
.hero-form input[type="email"],
.cta-form input[type="email"],
.hero-form select,
.cta-form select {
  flex: 1 1 200px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 82%, transparent);
  backdrop-filter: blur(6px);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 0.96rem;
}
.hero-form input:focus, .cta-form input:focus,
.hero-form select:focus, .cta-form select:focus {
  outline: none;
  border-color: var(--accent-2);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent-2) 25%, transparent);
}
.hidden-field { display: none; }
.hero-note { margin-top: 14px; font-size: 0.82rem; color: var(--muted); }
.form-status { min-height: 1.2em; font-size: 0.9rem; margin-top: 10px; font-weight: 500; }
.form-status.ok { color: #29a06a; }
.form-status.err { color: #e5484d; }
[data-theme="dark"] .form-status.ok { color: #4ade80; }

/* ============================================================
   Aspiration marquee
   ============================================================ */
.aspire {
  padding: 40px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-2);
}
.aspire-label {
  text-align: center;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 22px;
}
.aspire-marquee {
  overflow: hidden;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
}
.aspire-track {
  display: flex;
  gap: 52px;
  width: max-content;
  animation: marquee 34s linear infinite;
}
.aspire-track span {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 500;
  color: var(--muted);
  opacity: 0.75;
  white-space: nowrap;
  transition: color 0.2s ease, opacity 0.2s ease;
}
.aspire-track span:hover { color: var(--text); opacity: 1; }
@keyframes marquee {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* ============================================================
   Mission
   ============================================================ */
.mission { padding: 96px 0; }
.mission-inner { max-width: 760px; }
.mission h2 {
  font-size: clamp(1.9rem, 3.6vw, 2.9rem);
  margin: 0 0 28px;
}
.mission-lead {
  font-size: 1.14rem;
  color: var(--muted);
  line-height: 1.7;
  margin: 0 0 18px;
}
.mission-lead strong { color: var(--text); font-weight: 600; }

/* ============================================================
   Section scaffolding
   ============================================================ */
.exposure, .frontiers, .personas, .how, .network, .resources, .roadmap, .signup-cta {
  padding: 92px 0;
}
.exposure h2, .frontiers h2, .personas h2, .how h2,
.resources h2, .roadmap h2 {
  font-size: clamp(1.7rem, 3.2vw, 2.5rem);
  margin: 0 0 10px;
}

/* ---- Exposure cards ---- */
.exposure { background: var(--bg-2); border-top: 1px solid var(--border); }
.exposure-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 22px;
}
.exposure-card {
  position: relative;
  padding: 30px 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.exposure-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  opacity: 0;
  transition: opacity 0.25s ease;
}
.exposure-card:hover {
  transform: translateY(-5px);
  border-color: color-mix(in srgb, var(--accent-2) 45%, var(--border));
  box-shadow: 0 24px 44px -28px rgba(0,0,0,0.5);
}
.exposure-card:hover::before { opacity: 1; }
.ex-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px; height: 46px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--accent-2) 14%, transparent);
  color: var(--accent-2);
  margin-bottom: 18px;
}
.ex-icon svg { width: 24px; height: 24px; }
.exposure-card h3 { margin: 0 0 10px; font-size: 1.2rem; }
.exposure-card p { margin: 0; color: var(--muted); font-size: 0.95rem; }
.exposure-card.is-link, .roadmap-card.is-link { text-decoration: none; color: inherit; display: block; }
.exposure-card.is-link h3, .roadmap-card.is-link h3 { color: var(--text); }
.card-link {
  display: inline-block;
  margin-top: 14px;
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--accent-2);
  transition: transform 0.2s ease;
}
.is-link:hover .card-link { transform: translateX(4px); }

/* ---- Frontier tags ---- */
.frontier-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.frontier-tag {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 12px 20px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: default;
  transition: transform 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}
.frontier-tag:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--accent-3) 55%, var(--border));
  color: var(--accent-3);
  box-shadow: 0 12px 26px -18px color-mix(in srgb, var(--accent-3) 80%, transparent);
}

/* ---- Personas ---- */
.persona-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 22px;
}
.persona-card {
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.persona-card:hover {
  transform: translateY(-5px);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
  box-shadow: 0 24px 44px -28px rgba(0,0,0,0.5);
}
.persona-icon {
  font-size: 1.9rem;
  display: inline-block;
  margin-bottom: 14px;
  transition: transform 0.25s ease;
}
.persona-card:hover .persona-icon { transform: scale(1.18) rotate(-5deg); }
.persona-card h3 { margin: 0 0 9px; font-size: 1.14rem; }
.persona-card p { margin: 0; color: var(--muted); font-size: 0.93rem; }

/* ---- Support band ---- */
.support-band {
  padding: 68px 0;
  background:
    radial-gradient(600px 300px at 20% 0%, color-mix(in srgb, var(--accent) 12%, transparent), transparent),
    var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.support-inner { max-width: 720px; }
.support-band h2 { font-family: var(--font-serif); font-size: clamp(1.5rem, 2.8vw, 2rem); margin: 0 0 16px; }
.support-band p { color: var(--muted); margin: 0 0 14px; font-size: 1.02rem; }
.support-disclaimer { font-size: 0.84rem !important; opacity: 0.8; }

/* ---- How it works ---- */
.how { background: var(--bg-2); }
.how-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 28px;
  margin-top: 20px;
}
.how-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  border-radius: 50%;
  background: linear-gradient(180deg, var(--accent-soft), var(--accent));
  color: var(--accent-text);
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.05rem;
  margin-bottom: 16px;
}
.how-step h3 { margin: 0 0 9px; font-size: 1.16rem; }
.how-step p { margin: 0; color: var(--muted); font-size: 0.95rem; }

/* ---- Network ---- */
.network-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.network-copy h2 { font-size: clamp(1.6rem, 3vw, 2.3rem); margin: 0 0 16px; }
.network-copy p { color: var(--muted); font-size: 1.04rem; }
.network-viz svg { width: 100%; height: auto; overflow: visible; }
.net-nodes circle {
  fill: var(--accent-2);
  animation: node-pulse 3.2s ease-in-out infinite;
  transform-origin: center;
  transform-box: fill-box;
  filter: drop-shadow(0 0 6px color-mix(in srgb, var(--accent-2) 60%, transparent));
}
.net-nodes circle.hub { fill: var(--accent); filter: drop-shadow(0 0 10px color-mix(in srgb, var(--accent) 70%, transparent)); }
@keyframes node-pulse {
  0%, 100% { opacity: 0.65; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.28); }
}
.net-lines line { stroke-dasharray: 6 7; animation: line-flow 7s linear infinite; }
@keyframes line-flow { to { stroke-dashoffset: -130; } }

/* ---- Filter chips ---- */
.filter-chips { display: flex; flex-wrap: wrap; gap: 9px; margin-bottom: 32px; }
.chip {
  font-family: var(--font-sans);
  padding: 9px 18px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}
.chip:hover { border-color: var(--accent-2); color: var(--text); }
.chip.is-active {
  background: var(--accent-2);
  border-color: var(--accent-2);
  color: #04222a;
}
.resource-category { margin-bottom: 40px; }
.resource-category.is-hidden { display: none; }
.resource-category h3 {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 700;
  color: var(--accent-2);
  margin: 0 0 16px;
}
.resource-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 0 32px;
}
.resource-list li {
  padding: 13px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.93rem;
  color: var(--muted);
}
.resource-list a { color: var(--text); font-weight: 600; text-decoration: none; }
.resource-list a:hover { color: var(--accent-2); }

/* ---- Roadmap ---- */
.roadmap { background: var(--bg-2); }
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 22px;
}
.roadmap-card {
  padding: 26px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.roadmap-card:hover { transform: translateY(-4px); box-shadow: 0 20px 40px -28px rgba(0,0,0,0.5); }
.roadmap-card h3 { margin: 12px 0 9px; font-size: 1.16rem; }
.roadmap-card p { margin: 0; color: var(--muted); font-size: 0.93rem; }
.tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 11px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--muted);
  border: 1px solid var(--border);
}
.tag-live {
  background: color-mix(in srgb, var(--accent-2) 18%, transparent);
  color: var(--accent-2);
  border-color: color-mix(in srgb, var(--accent-2) 40%, transparent);
}

/* ---- Signup CTA ---- */
.signup-cta {
  background:
    radial-gradient(700px 360px at 80% 100%, color-mix(in srgb, var(--accent-2) 14%, transparent), transparent),
    radial-gradient(700px 360px at 15% 0%, color-mix(in srgb, var(--accent) 12%, transparent), transparent),
    var(--bg);
  border-top: 1px solid var(--border);
}
.signup-inner { max-width: 680px; }
.signup-cta h2 { font-size: clamp(1.9rem, 3.6vw, 2.8rem); margin: 0 0 12px; }
.signup-cta p { color: var(--muted); margin: 0 0 26px; font-size: 1.05rem; }

/* ---- Footer ---- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  background: var(--bg-2);
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 20px;
}
.footer-brand .logo { font-size: 1.15rem; }
.footer-brand p { margin: 8px 0 0; color: var(--muted); font-size: 0.9rem; }
.footer-nav { display: flex; gap: 20px; }
.footer-nav a { color: var(--muted); text-decoration: none; font-size: 0.88rem; transition: color 0.15s ease; }
.footer-nav a:hover { color: var(--text); }
.footer-meta { display: flex; flex-direction: column; gap: 4px; text-align: right; color: var(--muted); font-size: 0.85rem; }

/* ============================================================
   Article / Playbook page
   ============================================================ */
.article-hero {
  padding: 72px 0 56px;
  background:
    radial-gradient(900px 420px at 78% -10%, color-mix(in srgb, var(--accent-2) 15%, transparent), transparent 60%),
    radial-gradient(760px 380px at 8% 0%, color-mix(in srgb, var(--accent) 11%, transparent), transparent 55%),
    var(--bg);
  border-bottom: 1px solid var(--border);
}
.crumb { font-size: 0.82rem; color: var(--muted); margin: 0 0 22px; }
.crumb a { color: var(--muted); text-decoration: none; }
.crumb a:hover { color: var(--text); }
.crumb span { margin: 0 6px; opacity: 0.6; }
.article-hero h1 { font-size: clamp(2.1rem, 4.6vw, 3.4rem); margin: 0 0 20px; max-width: 900px; }
.article-lead {
  font-size: clamp(1.05rem, 1.6vw, 1.24rem);
  color: var(--muted);
  max-width: 720px;
  line-height: 1.62;
  margin: 0 0 18px;
}
.article-meta { font-size: 0.84rem; color: var(--muted); opacity: 0.85; margin: 0; }

.article-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 56px;
  padding-top: 56px;
  padding-bottom: 40px;
  align-items: start;
}
.toc {
  position: sticky;
  top: 92px;
  align-self: start;
}
.toc-title {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-weight: 700;
  color: var(--accent-2);
  margin: 0 0 14px;
}
.toc nav { display: flex; flex-direction: column; gap: 2px; border-left: 1px solid var(--border); }
.toc nav a {
  font-size: 0.86rem;
  color: var(--muted);
  text-decoration: none;
  padding: 7px 0 7px 16px;
  margin-left: -1px;
  border-left: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.toc nav a:hover { color: var(--text); border-left-color: var(--accent-2); }

.article-body { max-width: 720px; }
.article-body > p:first-child { font-size: 1.12rem; color: var(--muted); }
.article-body section { margin: 46px 0; scroll-margin-top: 92px; }
.article-body h2 {
  font-size: clamp(1.5rem, 2.6vw, 1.9rem);
  margin: 0 0 16px;
  padding-bottom: 4px;
}
.article-body h3 {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 1.06rem;
  margin: 26px 0 10px;
  color: var(--text);
}
.article-body p { color: var(--muted); font-size: 1.02rem; line-height: 1.72; margin: 0 0 16px; }
.article-body strong { color: var(--text); font-weight: 600; }
.article-body a { color: var(--accent-2); text-decoration: none; border-bottom: 1px solid color-mix(in srgb, var(--accent-2) 40%, transparent); }
.article-body a:hover { border-bottom-color: var(--accent-2); }

.prose-list { margin: 0 0 16px; padding-left: 22px; }
.prose-list li { color: var(--muted); font-size: 1.02rem; line-height: 1.68; margin-bottom: 10px; }
.prose-list.numbered { list-style: decimal; }

/* Callouts */
.callout {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-2);
  background: var(--surface);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 20px 24px;
  margin: 24px 0;
}
.callout p { margin: 0 0 8px; font-size: 0.98rem; }
.callout p:last-child { margin-bottom: 0; }
.callout-key { border-left-color: var(--accent); background: color-mix(in srgb, var(--accent) 7%, var(--surface)); }
.callout-label {
  font-size: 0.72rem !important;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
  color: var(--accent) !important;
}
.callout-code { background: var(--surface-2); border-left-color: var(--muted); }
.callout-code p { font-family: var(--font-sans); font-size: 0.92rem; line-height: 1.6; color: var(--muted); }
.callout-code strong { color: var(--text); }

/* Timeline */
.timeline { list-style: none; margin: 24px 0; padding: 0; }
.timeline li {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 20px;
  padding: 16px 0;
  border-top: 1px solid var(--border);
  align-items: baseline;
}
.timeline li:last-child { border-bottom: 1px solid var(--border); }
.tl-when { font-weight: 600; color: var(--accent-2); font-size: 0.9rem; }
.tl-what { color: var(--muted); font-size: 0.98rem; line-height: 1.6; }

/* Region comparison */
.compare { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 18px; margin: 24px 0; }
.compare-col {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 22px;
}
.compare-col h3 { margin: 0 0 12px; font-family: var(--font-serif); font-weight: 500; font-size: 1.2rem; color: var(--text); }
.compare-col ul { margin: 0; padding-left: 18px; }
.compare-col li { color: var(--muted); font-size: 0.92rem; line-height: 1.55; margin-bottom: 8px; }

/* ============================================================
   Resources library page
   ============================================================ */
.lib-intro { max-width: 720px; margin: 0 0 8px; }
.resources-page { padding: 48px 0 80px; }
.resources-page .filter-chips { position: sticky; top: 76px; z-index: 5; background: color-mix(in srgb, var(--bg) 92%, transparent); backdrop-filter: blur(10px); padding: 12px 0; margin: 0 0 24px; }
.cat-count { font-family: var(--font-sans); font-size: 0.7rem; font-weight: 600; color: var(--muted); border: 1px solid var(--border); border-radius: 999px; padding: 2px 8px; margin-left: 10px; vertical-align: middle; }

/* YouTube channel cards */
.yt-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; }
.yt-card {
  display: flex; gap: 14px; align-items: flex-start;
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  text-decoration: none;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.yt-card:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent-2) 50%, var(--border)); box-shadow: 0 14px 30px -22px rgba(0,0,0,0.5); }
.yt-play {
  flex: 0 0 auto; width: 42px; height: 42px; border-radius: 11px;
  display: flex; align-items: center; justify-content: center;
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  color: var(--accent);
}
.yt-play svg { width: 20px; height: 20px; }
.yt-card h4 { margin: 0; font-family: var(--font-sans); font-weight: 600; font-size: 0.98rem; color: var(--text); }
.yt-handle { font-size: 0.78rem; color: var(--accent-2); font-weight: 500; }
.yt-card p { margin: 5px 0 0; font-size: 0.86rem; color: var(--muted); line-height: 1.5; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
  .article-layout { grid-template-columns: 1fr; gap: 0; }
  .toc { display: none; }
}
@media (max-width: 820px) {
  .network-inner { grid-template-columns: 1fr; }
  .network-viz { max-width: 440px; }
}
@media (max-width: 720px) {
  .site-nav a:not(.btn) { display: none; }
  .hero { padding: 84px 0 64px; }
  .mission, .exposure, .frontiers, .personas, .how, .network, .resources, .roadmap, .signup-cta { padding: 64px 0; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-meta { text-align: left; }
  .timeline li { grid-template-columns: 1fr; gap: 4px; }
}