:root{
  --sg-header-h:58px;
  --sg-radius:10px;
  --sg-control:40px;
  --sg-header-bg:hsla(42,33%,97%,.76);
  --sg-header-bg-scrolled:hsla(42,33%,97%,.94);
  --sg-header-border:hsla(214,12%,18%,.11);
  --sg-surface:hsl(0,0%,100%);
  --sg-surface-hover:hsl(40,17%,94%);
  --sg-text:hsl(218,15%,16%);
  --sg-muted:hsl(216,7%,43%);
  --sg-accent:hsl(124,29%,31%);
  --sg-focus:hsla(124,29%,31%,.2);
  --sg-backdrop:hsla(116,22%,8%,.58);
  --sg-shadow:0 18px 54px hsla(116,22%,8%,.18);
  --sg-hero-from:hsl(126,30%,20%);
  --sg-hero-to:hsl(124,24%,36%);
}

[data-theme="dark"]{
  --sg-header-bg:hsla(220,11%,9%,.92);
  --sg-header-bg-scrolled:hsla(220,11%,9%,.94);
  --sg-header-border:hsla(0,0%,100%,.09);
  --sg-surface:hsl(220,10%,14%);
  --sg-surface-hover:hsl(220,9%,18%);
  --sg-text:hsl(42,18%,93%);
  --sg-muted:hsl(218,8%,66%);
  --sg-accent:hsl(142,43%,63%);
  --sg-focus:hsla(142,43%,63%,.2);
  --sg-backdrop:hsla(220,24%,4%,.76);
  --sg-shadow:0 22px 64px hsla(0,0%,0%,.42);
}

body[data-sg-section="ai"]{
  --sg-accent:hsl(173,72%,29%);
  --sg-focus:hsla(173,72%,38%,.2);
  --sg-hero-from:hsl(178,67%,20%);
  --sg-hero-to:hsl(165,55%,34%);
}
[data-theme="dark"] body[data-sg-section="ai"]{--sg-accent:hsl(169,54%,51%)}

body[data-sg-section="high-concurrency"]{
  --sg-accent:hsl(190,90%,35%);
  --sg-focus:hsla(190,90%,43%,.2);
  --sg-hero-from:hsl(213,78%,20%);
  --sg-hero-to:hsl(190,86%,36%);
}
[data-theme="dark"] body[data-sg-section="high-concurrency"]{--sg-accent:hsl(188,86%,57%)}

body[data-sg-section="longtail"]{
  --sg-accent:hsl(24,68%,45%);
  --sg-focus:hsla(24,68%,45%,.2);
  --sg-hero-from:hsl(26,52%,29%);
  --sg-hero-to:hsl(38,58%,49%);
}
[data-theme="dark"] body[data-sg-section="longtail"]{--sg-accent:hsl(35,79%,62%)}

body[data-sg-section="netflix"]{
  --sg-accent:hsl(357,92%,52%);
  --sg-focus:hsla(357,92%,52%,.22);
  --sg-hero-from:hsl(220,10%,8%);
  --sg-hero-to:hsl(356,49%,22%);
}
[data-theme="dark"] body[data-sg-section="netflix"]{--sg-accent:hsl(357,94%,62%)}

body[data-sg-section="disorder"]{
  --sg-accent:hsl(35,67%,52%);
  --sg-focus:hsla(35,67%,52%,.22);
  --sg-hero-from:hsl(216,59%,16%);
  --sg-hero-to:hsl(211,54%,28%);
}
[data-theme="dark"] body[data-sg-section="disorder"]{--sg-accent:hsl(38,82%,68%)}

body[data-sg-section="metacognition"]{
  --sg-accent:hsl(269,42%,48%);
  --sg-focus:hsla(269,42%,48%,.2);
  --sg-hero-from:hsl(238,31%,20%);
  --sg-hero-to:hsl(269,33%,34%);
}
[data-theme="dark"] body[data-sg-section="metacognition"]{--sg-accent:hsl(269,57%,70%)}

body[data-sg-section="ai-native"]{
  --sg-accent:hsl(145,44%,35%);
  --sg-focus:hsla(145,44%,35%,.2);
  --sg-hero-from:hsl(151,45%,18%);
  --sg-hero-to:hsl(143,36%,34%);
}
[data-theme="dark"] body[data-sg-section="ai-native"]{--sg-accent:hsl(145,48%,59%)}

body[data-sg-section="black-and-white"]{
  --sg-accent:hsl(0,0%,28%);
  --sg-focus:hsla(0,0%,28%,.2);
  --sg-hero-from:hsl(0,0%,8%);
  --sg-hero-to:hsl(0,0%,20%);
}
[data-theme="dark"] body[data-sg-section="black-and-white"]{--sg-accent:hsl(42,35%,68%);--sg-focus:hsla(42,35%,68%,.22)}

body[data-sg-section="longtail"]{overflow-x:hidden}
body[data-sg-section="longtail"] > nav:not(.sg-global-header){display:none!important}

body[data-sg-page] > .topbar:not(.sg-global-header),
body[data-sg-page] > .topnav,
body[data-sg-page] > .nav:not(.sg-global-header){display:none!important}
body[data-sg-page] > .search-overlay:not(.sg-search-overlay),
body[data-sg-page] > .search-layer:not(.sg-search-overlay){display:none!important}

.sg-global-header{
  position:fixed!important;
  inset:0 0 auto 0!important;
  z-index:10000!important;
  height:var(--sg-header-h)!important;
  padding:0!important;
  margin:0!important;
  border:0!important;
  border-bottom:1px solid transparent!important;
  background:var(--sg-header-bg)!important;
  color:var(--sg-text)!important;
  box-shadow:none!important;
  backdrop-filter:blur(18px) saturate(135%);
  -webkit-backdrop-filter:blur(18px) saturate(135%);
  text-align:left!important;
  transition:background .22s ease,border-color .22s ease,box-shadow .22s ease!important;
}
.sg-global-header.is-scrolled{
  border-bottom-color:var(--sg-header-border)!important;
  background:var(--sg-header-bg-scrolled)!important;
  box-shadow:0 8px 28px hsla(220,18%,8%,.08)!important;
}
[data-theme="dark"] .sg-global-header.is-scrolled{box-shadow:0 10px 34px hsla(0,0%,0%,.24)!important}

.sg-global-header::before,.sg-global-header::after{content:none!important;display:none!important}

.sg-global-inner{
  width:100%;
  max-width:1280px;
  height:100%;
  margin:0 auto;
  padding:0 24px;
  display:grid;
  grid-template-columns:minmax(116px,1fr) minmax(0,2.2fr) minmax(220px,1fr);
  align-items:center;
  gap:16px;
}

.sg-global-left,.sg-global-actions{display:flex;align-items:center;min-width:0}
.sg-global-left{justify-content:flex-start}
.sg-global-actions{justify-content:flex-end;gap:6px}

.sg-back-link{
  display:inline-flex;
  align-items:center;
  gap:6px;
  min-width:0;
  color:var(--sg-muted)!important;
  font-size:12px;
  font-weight:650;
  line-height:1;
  text-decoration:none!important;
  white-space:nowrap;
  transition:color .18s ease,transform .18s ease!important;
}
.sg-back-link:hover{color:var(--sg-accent)!important;transform:translateX(-2px)}
.sg-back-link:focus-visible{outline:3px solid var(--sg-focus);outline-offset:5px;border-radius:6px}
.sg-back-link svg{width:17px;height:17px;flex:0 0 auto;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}

.sg-global-context{
  min-width:0;
  display:flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  overflow:hidden;
  color:var(--sg-text);
  font-size:14px;
  line-height:1.2;
  white-space:nowrap;
}
.sg-topic-mark{width:25px;height:25px;display:grid;place-items:center;flex:0 0 auto;border-radius:8px;background:var(--sg-focus);color:var(--sg-accent)}
.sg-topic-mark svg{width:15px;height:15px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.sg-topic-name{flex:0 0 auto;color:var(--sg-accent);font-size:inherit;font-weight:700;letter-spacing:0}
.sg-context-divider{flex:0 0 auto;color:var(--sg-header-border);font-size:12px;font-weight:500}
.sg-current-title{min-width:0;overflow:hidden;color:var(--sg-text);font-size:inherit;font-weight:700;text-overflow:ellipsis;white-space:nowrap}

.sg-icon-button{
  width:var(--sg-control)!important;
  height:var(--sg-control)!important;
  min-width:var(--sg-control)!important;
  padding:0!important;
  margin:0!important;
  display:inline-flex!important;
  align-items:center!important;
  justify-content:center!important;
  border:1px solid transparent!important;
  border-radius:var(--sg-radius)!important;
  background:transparent!important;
  color:var(--sg-muted)!important;
  box-shadow:none!important;
  cursor:pointer;
  text-decoration:none!important;
  transition:color .18s ease,border-color .18s ease,background .18s ease,transform .18s ease!important;
}
.sg-icon-button:hover{
  color:var(--sg-accent)!important;
  border-color:transparent!important;
  background:var(--sg-surface-hover)!important;
  transform:translateY(-1px)!important;
}
.sg-icon-button:focus-visible{outline:3px solid var(--sg-focus)!important;outline-offset:2px!important}
.sg-icon-button svg{width:19px!important;height:19px!important;fill:none!important;stroke:currentColor!important;stroke-width:1.8!important;stroke-linecap:round!important;stroke-linejoin:round!important}
.sg-theme-sun{display:none}
[data-theme="dark"] .sg-theme-moon{display:none}
[data-theme="dark"] .sg-theme-sun{display:block}

.sg-home-brand{height:40px;display:inline-flex;align-items:center;gap:7px;padding:0 4px 0 6px;flex:0 0 auto;color:var(--sg-text)!important;text-decoration:none!important;border-radius:10px;transition:background .18s ease,color .18s ease}
.sg-home-brand:hover{background:var(--sg-surface-hover);color:var(--sg-accent)!important}
.sg-home-brand:focus-visible{outline:3px solid var(--sg-focus);outline-offset:2px}
.sg-home-mark{width:27px;height:27px;display:grid;place-items:center;color:var(--sg-accent)}
.sg-home-mark svg{width:27px;height:27px;overflow:visible;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.sg-home-mark .sg-seed{fill:currentColor;stroke:none;opacity:.18}.sg-home-mark .sg-leaf-soft{fill:currentColor;stroke:none;opacity:.72}.sg-home-mark .sg-leaf{fill:currentColor;stroke:none}
.sg-home-wordmark{font-family:'Bodoni 72','Didot','Baskerville','Times New Roman',serif;font-size:14px;line-height:1;letter-spacing:-.035em}
.sg-home-wordmark span{font-weight:650}.sg-home-wordmark em{color:var(--sg-accent);font-weight:500}
.sg-reading-progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;overflow:hidden;opacity:.9;transition:opacity .18s ease}
.sg-reading-progress.is-hidden{opacity:0}
.sg-reading-progress span{display:block;width:100%;height:100%;transform:scaleX(0);transform-origin:left center;background:var(--sg-accent);box-shadow:0 0 10px var(--sg-focus);will-change:transform}

body[data-sg-page]:not([data-sg-home]) h1{text-align:left!important}
body[data-sg-page]:not([data-sg-home]) .article-header,
body[data-sg-page]:not([data-sg-home]) .chapter-header,
body[data-sg-page]:not([data-sg-home]) .ch-hero-inner,
body[data-sg-page]:not([data-sg-home]) .hero-inner{text-align:left!important}
body[data-sg-page]:not([data-sg-home]) .article-header .lead,
body[data-sg-page]:not([data-sg-home]) .ch-hero .thesis,
body[data-sg-page]:not([data-sg-home]) .hero .sub{margin-left:0!important;margin-right:0!important}

body[data-sg-section="ai"] .overview-copy,
body[data-sg-section="ai"] .overview-copy h1{text-align:left!important}

/* Neutral dark reading foundation. Topic colors remain accents, not page tints. */
[data-theme="dark"] body[data-sg-page]:not([data-sg-home]){
  --bg-main:hsl(220,11%,9%);
  --bg-secondary:hsl(220,10%,12%);
  --bg-card:hsl(220,9%,15%);
  --border:hsla(0,0%,100%,.10);
  --divider:hsla(0,0%,100%,.075);
  --text-heading:hsl(42,18%,94%);
  --text-body:hsl(218,12%,82%);
  --text-secondary:hsl(218,8%,64%);
  --topbar:var(--sg-header-bg-scrolled);
}
[data-theme="dark"] body[data-sg-section="disorder"]{
  --fad-paper:hsl(220,11%,9%);--fad-surface:hsl(220,9%,15%);--fad-surface-2:hsl(220,9%,18%);
  --fad-border:hsla(0,0%,100%,.10);--fad-line:hsla(0,0%,100%,.075);--fad-ink:hsl(42,18%,94%);
  --fad-body:hsl(218,12%,82%);--fad-muted:hsl(218,8%,64%);
}
[data-theme="dark"] body[data-sg-section="metacognition"]{
  --primary:hsl(269,57%,70%);--primary-hover:hsl(269,65%,78%);--primary-soft:hsla(269,57%,70%,.14);
  --ink:hsl(42,18%,94%);--text:hsl(218,12%,82%);--muted:hsl(218,8%,64%);--faint:hsl(218,7%,47%);
  --bg:hsl(220,11%,9%);--bg-alt:hsl(220,10%,12%);--card:hsl(220,9%,15%);--card-2:hsl(220,9%,18%);
  --line:hsla(0,0%,100%,.10);--line-strong:hsla(0,0%,100%,.16);--shadow-hover:hsla(269,57%,70%,.22);
}
[data-theme="dark"] body[data-sg-section="ai-native"]{
  --primary:hsl(145,48%,59%);--primary-hover:hsl(145,53%,69%);--primary-light:hsla(145,48%,59%,.14);
  --bg-main:hsl(220,11%,9%);--bg-secondary:hsl(220,10%,12%);--bg-card:hsl(220,9%,15%);--bg-code:hsl(220,12%,11%);
  --border:hsla(0,0%,100%,.10);--divider:hsla(0,0%,100%,.075);--text-heading:hsl(42,18%,94%);
  --text-body:hsl(218,12%,82%);--text-secondary:hsl(218,8%,64%);--nav-bg:var(--sg-header-bg-scrolled);
}
[data-theme="dark"] body[data-sg-section="longtail"]{
  --ink:hsl(42,18%,94%);--ink-soft:hsl(218,12%,82%);--muted:hsl(218,8%,64%);
  --paper:hsl(220,11%,9%);--card:hsl(220,9%,15%);--line:hsla(0,0%,100%,.10);--tail-soft:hsla(35,79%,62%,.14);
}

body[data-sg-page] .hero,
body[data-sg-page] .ch-hero,
body[data-sg-page] .overview-hero{
  background-color:var(--sg-hero-from)!important;
  background-image:linear-gradient(135deg,var(--sg-hero-from),var(--sg-hero-to))!important;
}
body[data-sg-section="netflix"] .hero{
  background:
    radial-gradient(900px 520px at 50% -8%,var(--red-glow),transparent 60%),
    linear-gradient(180deg,var(--ink) 0%,var(--ink-2) 100%)!important;
}
body[data-sg-section="netflix"] .hero::after{
  content:""!important;
  display:block!important;
  position:absolute!important;
  inset:0!important;
  background:radial-gradient(600px 380px at 85% 110%,rgba(245,197,24,.08),transparent 60%)!important;
  pointer-events:none!important;
}
body[data-sg-section="netflix"] .ch-hero{
  background:
    radial-gradient(800px 420px at 18% -10%,var(--red-glow),transparent 58%),
    linear-gradient(180deg,var(--ink-2),var(--ink))!important;
}
body[data-sg-section="longtail"] > header:not(.sg-global-header){
  padding-top:calc(var(--sg-header-h) + 48px)!important;
  background-color:var(--sg-hero-from)!important;
  background-image:linear-gradient(135deg,var(--sg-hero-from),var(--sg-hero-to))!important;
  color:hsl(0,0%,100%)!important;
}
body[data-sg-section="longtail"] > header:not(.sg-global-header) .q,
body[data-sg-section="longtail"] > header:not(.sg-global-header) .sub{color:hsla(0,0%,100%,.82)!important}
body[data-sg-section="longtail"] > header:not(.sg-global-header) .hero-tags .t{
  color:hsl(0,0%,100%)!important;
  background:hsla(0,0%,100%,.1)!important;
  border-color:hsla(0,0%,100%,.25)!important;
  box-shadow:none!important;
}

body[data-sg-page]:not([data-sg-home]) .hero-grid,
body[data-sg-page]:not([data-sg-home]) .hero .orb,
body[data-sg-page]:not([data-sg-home]) .hero .sprout,
body[data-sg-page]:not([data-sg-home]) .hero::before,
body[data-sg-page]:not([data-sg-home]) .hero::after,
body[data-sg-page]:not([data-sg-home]) .ch-hero::before,
body[data-sg-page]:not([data-sg-home]) .ch-hero::after,
body[data-sg-page]:not([data-sg-home]) .overview-hero::before,
body[data-sg-page]:not([data-sg-home]) .overview-hero::after{
  content:none!important;
  display:none!important;
  background:none!important;
  background-image:none!important;
}
body[data-sg-section="high-concurrency"] .pulse-wrap{display:none!important}

body[data-sg-section="netflix"] .hero::after{
  content:""!important;
  display:block!important;
  position:absolute!important;
  inset:0!important;
  background:radial-gradient(600px 380px at 85% 110%,rgba(245,197,24,.08),transparent 60%)!important;
  pointer-events:none!important;
}

.sg-search-overlay[hidden]{display:none!important}
.sg-search-overlay{
  position:fixed;
  inset:0;
  z-index:11000;
  padding:10vh 20px 20px;
  background:var(--sg-backdrop);
  backdrop-filter:blur(4px);
  -webkit-backdrop-filter:blur(4px);
}
.sg-search-dialog{
  width:min(760px,100%);
  max-height:78vh;
  margin:0 auto;
  overflow:hidden;
  border:1px solid var(--sg-header-border);
  border-radius:14px;
  background:var(--sg-surface);
  color:var(--sg-text);
  box-shadow:var(--sg-shadow);
}
.sg-search-head{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:22px 24px 14px}
.sg-search-head h2{margin:0!important;color:var(--sg-text)!important;font-size:21px!important;line-height:1.3!important;text-align:left!important}
.sg-search-head p{margin:4px 0 0!important;color:var(--sg-muted)!important;font-size:12px!important}
.sg-search-field{
  height:52px;
  margin:0 24px 14px;
  padding:0 15px;
  display:flex;
  align-items:center;
  gap:10px;
  border:1px solid var(--sg-header-border);
  border-radius:10px;
  background:var(--sg-surface-hover);
}
.sg-search-field:focus-within{border-color:var(--sg-accent);box-shadow:0 0 0 3px var(--sg-focus)}
.sg-search-field svg{width:20px;height:20px;fill:none;stroke:var(--sg-muted);stroke-width:1.8;stroke-linecap:round}
.sg-search-field input{width:100%;min-width:0;padding:0!important;border:0!important;outline:0!important;background:transparent!important;color:var(--sg-text)!important;box-shadow:none!important;font:inherit!important}
.sg-search-results{max-height:52vh;overflow:auto;padding:0 16px 18px}
.sg-search-result{
  display:grid;
  grid-template-columns:1fr auto;
  gap:10px 18px;
  padding:14px 10px;
  border-top:1px solid var(--sg-header-border);
  color:var(--sg-text)!important;
  text-decoration:none!important;
}
.sg-search-result:hover{background:var(--sg-surface-hover)!important;color:var(--sg-text)!important}
.sg-search-result strong{display:block;color:var(--sg-text);font-size:15px;line-height:1.45}
.sg-search-result p{grid-column:1/2;margin:3px 0 0!important;color:var(--sg-muted)!important;font-size:12px!important;line-height:1.55!important}
.sg-search-topic{grid-column:2;grid-row:1/3;align-self:center;color:var(--sg-accent);font-size:12px;white-space:nowrap}
.sg-search-empty{padding:28px 10px;margin:0!important;color:var(--sg-muted)!important;text-align:center!important;font-size:14px!important}

@media(max-width:700px){
  body[data-sg-section="longtail"] .formula{display:grid!important;grid-template-columns:1fr!important;gap:10px!important}
  body[data-sg-section="longtail"] .formula .box{width:100%!important;min-width:0!important}
  body[data-sg-section="longtail"] .formula .op{width:auto!important;height:24px!important;justify-content:center!important;transform:none!important}
  body[data-sg-section="longtail"] table{display:block;max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch}
  .sg-global-inner{grid-template-columns:40px minmax(0,1fr) auto;gap:7px;padding:0 12px}
  .sg-back-link{width:40px;height:40px;justify-content:center}
  .sg-back-link span{display:none}
  .sg-global-context{justify-content:flex-start;gap:6px;font-size:12px}
  .sg-topic-mark{width:23px;height:23px;border-radius:7px}
  .sg-topic-name{font-size:0}
  .sg-topic-name::after{content:attr(data-short);font-size:12px}
  .sg-context-divider{display:none}
  .sg-current-title{font-size:inherit}
  .sg-global-actions{gap:2px}
  .sg-icon-button{--sg-control:36px}
  .sg-home-brand{width:38px;padding:0;justify-content:center}
  .sg-home-wordmark{display:none}
  .sg-search-overlay{padding:6vh 10px 10px}
  .sg-search-dialog{max-height:88vh}
  .sg-search-head{padding:18px 16px 12px}
  .sg-search-field{margin-left:14px;margin-right:14px}
  .sg-search-results{padding-left:10px;padding-right:10px}
  .sg-search-result{grid-template-columns:1fr}
  .sg-search-topic{grid-column:1;grid-row:auto;justify-self:start}
}

@media(max-width:420px){
  :root{--sg-control:34px}
  .sg-global-inner{grid-template-columns:34px minmax(0,1fr) auto;gap:4px;padding:0 8px}
  .sg-back-link{width:34px;height:36px}
  .sg-global-context{gap:5px}
  .sg-topic-mark{width:21px;height:21px}
  .sg-topic-name{display:none}
  .sg-global-header.is-topic-home .sg-topic-name{display:inline;max-width:78px;overflow:hidden;font-size:0;text-overflow:ellipsis;white-space:nowrap}
  .sg-global-header.is-topic-home .sg-topic-name::after{font-size:11px}
  .sg-current-title{font-size:11px}
  .sg-home-brand{width:34px;height:36px}
  .sg-home-mark,.sg-home-mark svg{width:24px;height:24px}
}

@media(prefers-reduced-motion:reduce){
  .sg-icon-button,.sg-global-header,.sg-back-link,.sg-home-brand{transition:none!important}
}