/* ===== Cognitive Civilization — neural-computational ===== */
:root{
  --bg: #0c0f17;
  --bg-2: #141823;
  --bg-3: #1c2233;
  --line: rgba(220,228,240,0.10);
  --line-2: rgba(220,228,240,0.22);
  --ink: #eaeef5;
  --ink-soft: #94a4bd;
  --blue: #5ab8e8;     /* electric — primary */
  --blue-2: #3a98c8;
  --capital: #5cd9a3;  /* market / value */
  --compute: #a07ac4;  /* GPU / abstraction */
  --neural: #e8a85c;   /* neuron firing */
  --rose: #d6688a;     /* inequality / friction */
}
[data-theme="light"]{
  --bg: #f4f5f7;
  --bg-2: #ffffff;
  --bg-3: #ebedf2;
  --line: rgba(15,20,32,0.10);
  --line-2: rgba(15,20,32,0.24);
  --ink: #14182a;
  --ink-soft: #4a5063;
  --blue: #1f6f9e;
  --blue-2: #155778;
  --capital: #1a8a5e;
  --compute: #5a4a8a;
  --neural: #a87a23;
  --rose: #a83d6e;
}

*{box-sizing: border-box}
html, body{margin: 0; padding: 0}
html{scroll-behavior: smooth; scroll-padding-top: 72px}
body{
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 17px; line-height: 1.65;
  color: var(--ink); background: var(--bg);
  background-image:
    radial-gradient(1100px 700px at 12% -10%, rgba(90,184,232,0.10), transparent 60%),
    radial-gradient(800px 600px at 105% 25%, rgba(160,122,196,0.07), transparent 60%),
    radial-gradient(700px 500px at 50% 110%, rgba(92,217,163,0.06), transparent 60%);
}
[data-theme="light"] body{
  background-image:
    radial-gradient(1100px 700px at 12% -10%, rgba(31,111,158,0.07), transparent 60%),
    radial-gradient(800px 600px at 105% 25%, rgba(90,74,138,0.05), transparent 60%),
    radial-gradient(700px 500px at 50% 110%, rgba(26,138,94,0.05), transparent 60%);
}

a{color: var(--ink); text-decoration: underline; text-decoration-color: var(--line-2); text-underline-offset: 3px}
a:hover{text-decoration-color: var(--blue)}
em{font-style: italic; color: var(--blue)}
code, .mono{font-family: "JetBrains Mono", ui-monospace, monospace}

/* Bilingual */
[lang="zh"]{display: none}
html[data-lang="zh"] [lang="en"]{display: none}
html[data-lang="zh"] [lang="zh"]{display: initial}
html svg [lang="zh"]{display: none}
html[data-lang="zh"] svg [lang="zh"]{display: inline}
html[data-lang="zh"] svg [lang="en"]{display: none}
html[data-lang="zh"]{font-family: "Noto Serif SC", "Source Han Serif SC", "Source Serif 4", Georgia, serif;}

/* Topbar */
.topbar{
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner{
  max-width: 1320px; margin: 0 auto;
  padding: 12px 24px;
  display: flex; align-items: center; gap: 18px;
}
.brand{
  display: flex; align-items: center; gap: 12px;
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 18px; font-weight: 600; letter-spacing: -.005em;
  text-decoration: none; color: var(--ink);
}
.brand .seal{
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 6px;
  background: var(--bg);
  border: 1.5px solid var(--blue);
  flex-shrink: 0;
}
.brand .seal svg{width: 26px; height: 26px; display: block}
.brand em{color: var(--blue); font-style: italic; font-weight: 600}
.nav{display: flex; gap: 14px; flex-wrap: wrap; margin-left: 8px}
.nav a{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .06em;
  text-transform: uppercase; text-decoration: none;
  color: var(--ink-soft);
  padding: 6px 0; border-bottom: 1px solid transparent;
}
.nav a:hover{color: var(--ink); border-bottom-color: var(--blue)}
.toolbar{margin-left: auto; display: flex; gap: 10px}
.lang-toggle, .theme-toggle{
  display: inline-flex; gap: 0;
  border: 1px solid var(--line); border-radius: 4px; overflow: hidden;
}
.lang-toggle button, .theme-toggle button{
  font-family: "JetBrains Mono", monospace; font-size: 11px;
  background: transparent; color: var(--ink-soft);
  border: none; border-right: 1px solid var(--line);
  padding: 5px 10px; cursor: pointer; letter-spacing: .04em;
}
.lang-toggle button:last-child, .theme-toggle button:last-child{border-right: none}
.lang-toggle button.active, .theme-toggle button.active{background: var(--blue); color: var(--bg)}

/* Hero */
.hero{ max-width: 1320px; margin: 0 auto; padding: 90px 24px 60px; position: relative; overflow: hidden;}
.hero-eyebrow{
  font-family: "JetBrains Mono", monospace;
  font-size: 12px; letter-spacing: .14em;
  color: var(--blue); text-transform: uppercase;
  margin-bottom: 24px;
}
.hero h1{
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-weight: 600;
  font-size: clamp(40px, 6vw, 78px);
  line-height: 1.04; letter-spacing: -.022em;
  margin: 0 0 18px; max-width: 18ch;
}
.hero h1 em{
  font-style: italic;
  background: linear-gradient(120deg, var(--blue), var(--compute), var(--capital));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-sub{
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 22px; line-height: 1.35;
  color: var(--ink-soft);
  font-weight: 400; max-width: 60ch;
  margin: 0 0 24px;
}
.hero-lede{
  font-size: 19px; line-height: 1.6;
  max-width: 64ch; color: var(--ink-soft);
  margin: 0 0 28px;
}
.hero-thesis{
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px; margin-top: 40px;
}
.hero-thesis div{
  border: 1px solid var(--line);
  background: var(--bg-2);
  padding: 18px; border-radius: 4px;
}
.hero-thesis div:nth-child(1){border-top: 3px solid var(--blue)}
.hero-thesis div:nth-child(2){border-top: 3px solid var(--neural)}
.hero-thesis div:nth-child(3){border-top: 3px solid var(--compute)}
.hero-thesis div:nth-child(4){border-top: 3px solid var(--capital)}
.hero-thesis strong{
  font-family: "JetBrains Mono", monospace; font-weight: 500;
  font-size: 11px; letter-spacing: .12em;
  color: var(--blue); text-transform: uppercase;
  display: block; margin-bottom: 8px;
}

/* Sections */
section{ max-width: 1320px; margin: 0 auto; padding: 72px 24px; border-top: 1px solid var(--line); }
section.no-rule{border-top: none}
.section-eyebrow{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .14em;
  color: var(--blue); text-transform: uppercase;
  margin: 0 0 14px;
}
.section-title{
  font-family: "Space Grotesk", system-ui, sans-serif; font-weight: 600;
  font-size: clamp(30px, 3.6vw, 46px);
  line-height: 1.12; margin: 0 0 16px;
  letter-spacing: -.018em;
}
.section-lede{
  font-size: 18px; line-height: 1.6; color: var(--ink-soft);
  max-width: 72ch; margin: 0 0 32px;
}
.epistemic{
  display: inline-block;
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .08em;
  color: var(--neural); text-transform: uppercase;
  border: 1px solid var(--line); border-radius: 3px;
  padding: 4px 10px; margin-bottom: 14px;
}

/* Brain ↔ Chip table */
.parallel-wrap{
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--bg-2); overflow: hidden;
}
table.parallel{
  width: 100%; border-collapse: collapse; font-size: 14px;
}
table.parallel th, table.parallel td{
  text-align: left; vertical-align: top;
  padding: 14px 18px; border-bottom: 1px solid var(--line);
}
table.parallel th{
  background: var(--bg-3);
  font-family: "JetBrains Mono", monospace; font-weight: 500;
  font-size: 10px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--blue);
}
table.parallel th:nth-child(2){color: var(--neural)}
table.parallel th:nth-child(3){color: var(--compute)}
table.parallel td:first-child{
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 16px; font-weight: 600;
  color: var(--ink); width: 22%;
}
table.parallel td:nth-child(2){font-family: "JetBrains Mono", monospace; font-size: 13px; color: var(--neural); width: 39%}
table.parallel td:nth-child(3){font-family: "JetBrains Mono", monospace; font-size: 13px; color: var(--compute); width: 39%}

/* Cards */
.grid{ display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid.two{grid-template-columns: repeat(auto-fit, minmax(380px, 1fr))}
.grid.three{grid-template-columns: repeat(auto-fit, minmax(320px, 1fr))}
.card{
  border: 1px solid var(--line);
  background: var(--bg-2);
  border-radius: 4px; padding: 22px;
  position: relative;
}
.card.blue{border-top: 3px solid var(--blue)}
.card.neural{border-top: 3px solid var(--neural)}
.card.compute{border-top: 3px solid var(--compute)}
.card.capital{border-top: 3px solid var(--capital)}
.card.rose{border-top: 3px solid var(--rose)}
.card h3{
  font-family: "Space Grotesk", system-ui, sans-serif; font-weight: 600;
  font-size: 22px; margin: 0 0 8px; line-height: 1.2;
  letter-spacing: -.005em;
}
.card .meta{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .08em;
  color: var(--blue); text-transform: uppercase;
  margin-bottom: 10px;
}
.card.neural .meta{color: var(--neural)}
.card.compute .meta{color: var(--compute)}
.card.capital .meta{color: var(--capital)}
.card.rose .meta{color: var(--rose)}
.card p{margin: 0 0 10px; line-height: 1.55}

/* Brain-chip SVG canvas */
.bio-canvas{
  border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg-2); overflow: hidden;
}
.bio-canvas svg{display: block; width: 100%; height: auto}

/* Phylogenetic ladder */
.ladder-wrap{
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--bg-2); overflow: hidden;
}
.ladder-row{
  display: grid; grid-template-columns: 220px 1fr;
  border-bottom: 1px solid var(--line);
}
.ladder-row:last-child{border-bottom: none}
.ladder-row > div{padding: 22px 24px}
.ladder-row .head{
  border-right: 1px dashed var(--line);
  background: color-mix(in oklab, var(--bg-3) 50%, var(--bg-2));
}
.ladder-row .head h4{
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 19px; font-weight: 600; margin: 0; line-height: 1.2;
}
.ladder-row .body p{margin: 0; line-height: 1.6}

/* Simulator */
.sim{
  display: grid; grid-template-columns: 320px 1fr; gap: 24px;
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--bg-2); padding: 24px;
}
.sim-controls .ctrl{margin-bottom: 18px}
.sim-controls label{
  font-family: "JetBrains Mono", monospace;
  font-size: 11px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink-soft); display: block; margin-bottom: 6px;
}
.sim-controls input[type="range"]{ width: 100%; accent-color: var(--blue); }
.sim-controls .val{
  font-family: "JetBrains Mono", monospace; font-size: 12px;
  color: var(--blue); float: right;
}
.sim-output{display: flex; flex-direction: column; gap: 16px}
.sim-meter{
  display: grid; grid-template-columns: 200px 1fr 60px;
  gap: 12px; align-items: center;
  font-family: "JetBrains Mono", monospace; font-size: 12px;
}
.sim-meter .bar{ height: 8px; background: var(--bg-3); border-radius: 4px; overflow: hidden; }
.sim-meter .bar-fill{
  height: 100%;
  background: linear-gradient(90deg, var(--compute), var(--blue), var(--capital));
  transition: width .25s ease;
}
.sim-meter .num{text-align: right; color: var(--blue)}
.sim-summary{
  margin-top: 8px; padding: 16px;
  background: var(--bg); border: 1px solid var(--line); border-radius: 4px;
  font-style: italic; color: var(--ink-soft); font-size: 15px; line-height: 1.6;
}

/* AI Q&A */
.ai-panel{
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--bg-2); padding: 24px;
}
.ai-q{
  font-family: "Space Grotesk", system-ui, sans-serif;
  font-size: 22px; font-weight: 600; margin: 0 0 8px;
  line-height: 1.25;
}
.ai-q::before{content: "◇ "; color: var(--blue)}
.ai-a{
  margin: 0 0 24px;
  padding-left: 22px; border-left: 2px solid var(--blue);
  font-size: 16px; line-height: 1.7; color: var(--ink-soft);
}
.ai-a:last-child{margin-bottom: 0}

/* Footer */
footer{
  max-width: 1320px; margin: 0 auto; padding: 48px 24px 64px;
  border-top: 1px solid var(--line);
  font-size: 14px; color: var(--ink-soft);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
footer a{color: var(--ink-soft)}

/* Responsive */
@media (max-width: 900px){
  .nav{display: none}
  .sim{grid-template-columns: 1fr}
  .ladder-row{grid-template-columns: 1fr}
  .ladder-row .head{border-right: none; border-bottom: 1px dashed var(--line)}
  table.parallel th, table.parallel td{font-size: 12px; padding: 10px 12px}
  table.parallel td:first-child{width: 30%}
}
@media (max-width: 600px){
  .topbar-inner{padding: 10px 16px; gap: 10px}
  .hero{padding: 56px 16px 36px}
  section{padding: 56px 16px}
}