/* ============================================================
   HUMAN OPERATING SYSTEM · 人类操作系统
   Design system — dark, futuristic, glass, neural
   ============================================================ */

:root {
  /* base canvas */
  --bg:        #05060c;
  --bg-2:      #080a14;
  --bg-3:      #0c1020;
  --panel:     rgba(18, 22, 40, 0.55);
  --panel-2:   rgba(26, 32, 56, 0.42);
  --stroke:    rgba(140, 170, 255, 0.12);
  --stroke-2:  rgba(140, 170, 255, 0.22);

  /* type */
  --ink:       #eaf0ff;
  --ink-dim:   rgba(225, 233, 255, 0.66);
  --ink-faint: rgba(200, 212, 255, 0.42);

  /* signal spectrum */
  --cyan:    #38e1ff;
  --blue:    #5b8cff;
  --violet:  #a878ff;
  --magenta: #e06bff;
  --rose:    #ff5d8f;
  --amber:   #ffb24a;
  --gold:    #ffd24a;
  --green:   #4ade80;
  --teal:    #2dd4bf;

  --accent:  var(--cyan);   /* per-section override */

  --maxw: 1180px;
  --font-display: "Space Grotesk", "Noto Sans SC", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Noto Sans SC", monospace;
  --font-sc: "Noto Sans SC", "Space Grotesk", sans-serif;
  --ease: cubic-bezier(.22,.61,.36,1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  background:
    radial-gradient(1200px 800px at 50% -10%, rgba(56,225,255,0.10), transparent 60%),
    radial-gradient(900px 700px at 85% 20%, rgba(168,120,255,0.08), transparent 55%),
    radial-gradient(900px 700px at 10% 60%, rgba(255,93,143,0.06), transparent 55%),
    var(--bg);
  color: var(--ink);
  font-family: var(--font-display);
  line-height: 1.65;
  overflow-x: hidden;
  letter-spacing: 0.01em;
}

/* grain / noise overlay */
body::after {
  content: "";
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
}

/* ---------- language switching ---------- */
.zh { display: none; }
body[data-lang="zh"] .en { display: none; }
body[data-lang="zh"] .zh { display: inline; }
body[data-lang="zh"] .zh.block { display: block; }
.en.block { display: block; }
body[data-lang="zh"] { font-family: var(--font-sc); }

/* ---------- top bar ---------- */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px clamp(16px, 4vw, 40px);
  background: linear-gradient(180deg, rgba(5,6,12,0.85), rgba(5,6,12,0));
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: background .4s var(--ease);
}
.topbar.solid { background: rgba(5,6,12,0.78); border-bottom: 1px solid var(--stroke); }
.brand { display: flex; align-items: center; gap: 11px; font-weight: 600; letter-spacing: .04em; cursor: pointer; }
.brand .glyph {
  width: 26px; height: 26px; border-radius: 7px; flex: none;
  background: conic-gradient(from 200deg, var(--cyan), var(--violet), var(--rose), var(--amber), var(--cyan));
  box-shadow: 0 0 18px rgba(56,225,255,0.5);
}
.brand .bt { font-size: 13.5px; }
.brand .bt small { display: block; font-size: 10px; color: var(--ink-faint); font-family: var(--font-mono); letter-spacing: .12em; }
.topbar-actions { display: flex; align-items: center; gap: 10px; }
.nav-toggle, .lang-btn {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: .08em;
  color: var(--ink-dim); background: var(--panel); border: 1px solid var(--stroke-2);
  padding: 8px 13px; border-radius: 999px; cursor: pointer; transition: all .25s var(--ease);
}
.nav-toggle:hover, .lang-btn:hover { color: var(--ink); border-color: var(--cyan); box-shadow: 0 0 16px rgba(56,225,255,0.25); }
.lang-btn b { color: var(--cyan); }

/* ---------- slide-out index ---------- */
.index-panel {
  position: fixed; top: 0; right: 0; bottom: 0; z-index: 60; width: min(380px, 86vw);
  background: rgba(8,10,20,0.92); backdrop-filter: blur(20px);
  border-left: 1px solid var(--stroke-2);
  transform: translateX(100%); transition: transform .5s var(--ease);
  padding: 78px 22px 30px; overflow-y: auto;
}
.index-panel.open { transform: translateX(0); }
.index-panel h3 { font-family: var(--font-mono); font-size: 11px; letter-spacing: .2em; color: var(--ink-faint); margin: 18px 0 8px; }
.index-panel a {
  display: flex; gap: 12px; align-items: baseline; color: var(--ink-dim); text-decoration: none;
  padding: 8px 10px; border-radius: 9px; font-size: 14px; transition: all .2s var(--ease);
}
.index-panel a:hover { background: var(--panel); color: var(--ink); }
.index-panel a .ix-n { font-family: var(--font-mono); font-size: 11px; color: var(--accent); width: 24px; flex: none; }
.scrim { position: fixed; inset: 0; z-index: 55; background: rgba(0,0,0,0.5); opacity: 0; pointer-events: none; transition: opacity .4s; }
.scrim.show { opacity: 1; pointer-events: auto; }

/* ---------- layout primitives ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(18px, 5vw, 40px); position: relative; z-index: 2; }
section { position: relative; z-index: 2; }

/* progress rail */
.scroll-rail { position: fixed; left: 0; top: 0; height: 3px; z-index: 70;
  background: linear-gradient(90deg, var(--cyan), var(--violet), var(--rose)); width: 0; box-shadow: 0 0 12px var(--cyan); }

/* ---------- HERO ---------- */
.hero { min-height: 100vh; display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 120px 20px 80px; position: relative; }
#heroCanvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: 1; }
.hero-content { position: relative; z-index: 3; max-width: 920px; }
.hero .kicker { font-family: var(--font-mono); font-size: 12px; letter-spacing: .42em; color: var(--cyan); text-transform: uppercase; margin-bottom: 26px; opacity: 0; animation: fadeUp 1s var(--ease) .2s forwards; }
.hero h1 {
  font-size: clamp(2.6rem, 8vw, 6.2rem); font-weight: 700; line-height: 0.98; letter-spacing: -0.02em;
  background: linear-gradient(180deg, #ffffff 0%, #cfe2ff 55%, #8fb8ff 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  opacity: 0; animation: fadeUp 1.1s var(--ease) .35s forwards;
}
.hero h1 .zh { background: linear-gradient(180deg, #fff, #b9d4ff); -webkit-background-clip: text; background-clip: text; }
.hero .sub { font-size: clamp(1rem, 2.4vw, 1.5rem); color: var(--ink-dim); margin-top: 22px; font-weight: 400; opacity: 0; animation: fadeUp 1.1s var(--ease) .55s forwards; }
.hero .lede { max-width: 640px; margin: 26px auto 0; color: var(--ink-faint); font-size: clamp(.95rem, 1.6vw, 1.08rem); opacity: 0; animation: fadeUp 1.1s var(--ease) .75s forwards; }
.hero .scroll-cue { margin-top: 54px; font-family: var(--font-mono); font-size: 11px; letter-spacing: .25em; color: var(--ink-faint); opacity: 0; animation: fadeUp 1s var(--ease) 1s forwards; }
.hero .scroll-cue::after { content: ""; display: block; width: 1px; height: 46px; margin: 14px auto 0; background: linear-gradient(var(--cyan), transparent); animation: pulseLine 2.2s ease-in-out infinite; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(26px); } to { opacity: 1; transform: translateY(0); } }
@keyframes pulseLine { 0%,100% { opacity: .3; } 50% { opacity: 1; } }

/* ---------- section intro ---------- */
.sec-head { max-width: 760px; margin: 0 auto clamp(40px, 7vw, 80px); text-align: center; }
.sec-head .eyebrow { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .28em; color: var(--accent); text-transform: uppercase; }
.sec-head h2 { font-size: clamp(1.9rem, 5vw, 3.2rem); font-weight: 700; letter-spacing: -0.02em; margin: 14px 0 16px; line-height: 1.05; }
.sec-head p { color: var(--ink-dim); font-size: clamp(1rem, 1.8vw, 1.15rem); }

/* ---------- MODULES ---------- */
#modules { padding: clamp(60px, 9vw, 120px) 0; }
.module { padding: clamp(48px, 8vw, 90px) 0; position: relative; }
.module + .module { border-top: 1px solid var(--stroke); }
.module-inner { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 5vw, 64px); align-items: center; max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(18px, 5vw, 40px); }
.module:nth-child(even) .module-text { order: 2; }
.module-text .m-num { font-family: var(--font-mono); font-size: clamp(3rem, 9vw, 6rem); font-weight: 700; line-height: 1; letter-spacing: -.04em;
  background: linear-gradient(160deg, var(--accent), transparent 85%); -webkit-background-clip: text; background-clip: text; color: transparent; opacity: .9; }
.module-text .m-tag { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .22em; color: var(--accent); text-transform: uppercase; display: block; margin: 6px 0 12px; }
.module-text h3 { font-size: clamp(1.7rem, 4vw, 2.6rem); font-weight: 700; letter-spacing: -.02em; line-height: 1.08; }
.module-text .m-lede { color: var(--ink-dim); margin: 16px 0 22px; font-size: 1.05rem; }
.module-text ul { list-style: none; display: flex; flex-wrap: wrap; gap: 9px; }
.module-text ul li {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: .03em; color: var(--ink-dim);
  border: 1px solid var(--stroke-2); padding: 6px 12px; border-radius: 999px; background: var(--panel-2);
  transition: all .25s var(--ease);
}
.module-text ul li:hover { color: var(--ink); border-color: var(--accent); box-shadow: 0 0 14px -2px var(--accent); }

.viz-card {
  position: relative; border-radius: 20px; overflow: hidden;
  background: var(--panel); border: 1px solid var(--stroke-2);
  box-shadow: 0 30px 80px -40px rgba(0,0,0,0.9), inset 0 1px 0 rgba(255,255,255,0.04);
  backdrop-filter: blur(10px); min-height: 360px;
}
.viz-card::before { content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(420px 220px at 70% 0%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 70%); }
.viz-card canvas { display: block; width: 100%; }
.viz-head { display: flex; align-items: center; gap: 9px; padding: 14px 16px 0; font-family: var(--font-mono); font-size: 11px; letter-spacing: .12em; color: var(--ink-faint); }
.viz-head .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 10px var(--accent); }
.viz-controls { display: flex; flex-wrap: wrap; gap: 8px; padding: 12px 16px 16px; }
.viz-controls button, .chip {
  font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .04em; color: var(--ink-dim);
  background: var(--panel-2); border: 1px solid var(--stroke-2); padding: 7px 12px; border-radius: 8px; cursor: pointer;
  transition: all .2s var(--ease);
}
.viz-controls button:hover, .chip:hover { color: var(--ink); border-color: var(--accent); }
.viz-controls button.active, .chip.active { color: #05060c; background: var(--accent); border-color: var(--accent); font-weight: 600; }
.viz-controls input[type=range] { -webkit-appearance: none; appearance: none; height: 4px; border-radius: 4px;
  background: var(--stroke-2); outline: none; flex: 1; min-width: 110px; }
.viz-controls input[type=range]::-webkit-slider-thumb { -webkit-appearance: none; width: 16px; height: 16px; border-radius: 50%;
  background: var(--accent); cursor: pointer; box-shadow: 0 0 10px var(--accent); }
.viz-controls input[type=range]::-moz-range-thumb { width: 16px; height: 16px; border: none; border-radius: 50%; background: var(--accent); cursor: pointer; }
.viz-readout { font-family: var(--font-mono); font-size: 12px; color: var(--accent); padding: 0 16px 14px; }

@media (max-width: 820px) {
  .module-inner { grid-template-columns: 1fr; }
  .module:nth-child(even) .module-text { order: 0; }
}

/* ---------- reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(34px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* ---------- DASHBOARD ---------- */
#dashboard { padding: clamp(70px, 10vw, 140px) 0; background: linear-gradient(180deg, transparent, rgba(10,14,32,0.5), transparent); }
.dash-grid { display: grid; grid-template-columns: 360px 1fr; gap: 36px; align-items: start; }
.dash-canvas-wrap { position: relative; border-radius: 20px; background: var(--panel); border: 1px solid var(--stroke-2); overflow: hidden; aspect-ratio: 1/1; }
#dashCanvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.dash-controls { display: flex; flex-direction: column; gap: 14px; }
.dash-slider { background: var(--panel); border: 1px solid var(--stroke-2); border-radius: 14px; padding: 14px 16px; }
.dash-slider .ds-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 9px; }
.dash-slider .ds-name { font-weight: 600; font-size: 14px; }
.dash-slider .ds-name .em { font-size: 16px; margin-right: 7px; }
.dash-slider .ds-val { font-family: var(--font-mono); font-size: 12px; color: var(--accent); }
.dash-slider input[type=range] { -webkit-appearance: none; appearance: none; width: 100%; height: 4px; border-radius: 4px; background: var(--stroke-2); outline: none; }
.dash-slider input[type=range]::-webkit-slider-thumb { -webkit-appearance: none; width: 16px; height: 16px; border-radius: 50%; background: var(--accent); cursor: pointer; box-shadow: 0 0 12px var(--accent); }
.dash-slider input[type=range]::-moz-range-thumb { width: 16px; height: 16px; border: none; border-radius: 50%; background: var(--accent); cursor: pointer; }
.dash-note { grid-column: 1/-1; text-align: center; color: var(--ink-faint); font-family: var(--font-mono); font-size: 12px; margin-top: 8px; }
@media (max-width: 820px) { .dash-grid { grid-template-columns: 1fr; } }

/* ---------- KNOWLEDGE GRAPH ---------- */
#graph { padding: clamp(70px, 10vw, 140px) 0; }
.graph-stage { position: relative; border-radius: 22px; background: radial-gradient(circle at 50% 45%, rgba(16,22,46,0.7), rgba(6,8,16,0.4)); border: 1px solid var(--stroke-2); overflow: hidden; height: min(72vh, 680px); }
#graphCanvas { position: absolute; inset: 0; width: 100%; height: 100%; cursor: grab; }
.graph-tip { position: absolute; pointer-events: none; z-index: 5; background: rgba(8,10,20,0.94); border: 1px solid var(--stroke-2); border-radius: 12px; padding: 12px 14px; max-width: 280px; opacity: 0; transition: opacity .2s; backdrop-filter: blur(8px); }
.graph-tip h4 { font-size: 14px; margin-bottom: 5px; }
.graph-tip p { font-size: 12.5px; color: var(--ink-dim); line-height: 1.5; }
.graph-legend { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; margin-top: 22px; font-family: var(--font-mono); font-size: 12px; color: var(--ink-dim); }
.graph-legend span { display: inline-flex; align-items: center; gap: 7px; }
.graph-legend i { width: 10px; height: 10px; border-radius: 50%; }

/* ---------- AI GUIDE ---------- */
#guide { padding: clamp(70px, 10vw, 140px) 0; }
.guide-shell { max-width: 860px; margin: 0 auto; border-radius: 22px; background: var(--panel); border: 1px solid var(--stroke-2); overflow: hidden; backdrop-filter: blur(12px); }
.guide-head { padding: 18px 22px; border-bottom: 1px solid var(--stroke); display: flex; align-items: center; gap: 12px; }
.guide-head .orb { width: 34px; height: 34px; border-radius: 50%; flex: none; background: conic-gradient(from 0deg, var(--cyan), var(--violet), var(--magenta), var(--cyan)); box-shadow: 0 0 22px rgba(168,120,255,0.5); animation: spin 8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.guide-head .gt b { display: block; font-size: 15px; }
.guide-head .gt small { color: var(--ink-faint); font-family: var(--font-mono); font-size: 11px; letter-spacing: .1em; }
.guide-body { padding: 18px 22px; min-height: 220px; max-height: 420px; overflow-y: auto; }
.bubble { margin: 12px 0; max-width: 86%; padding: 13px 16px; border-radius: 16px; font-size: 14.5px; line-height: 1.62; animation: fadeUp .5s var(--ease); }
.bubble.user { margin-left: auto; background: linear-gradient(135deg, var(--blue), var(--violet)); color: #fff; border-bottom-right-radius: 5px; }
.bubble.ai { background: var(--panel-2); border: 1px solid var(--stroke-2); border-bottom-left-radius: 5px; color: var(--ink); }
.bubble.ai .tag { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: .12em; color: var(--accent); text-transform: uppercase; display: block; margin-bottom: 6px; }
.bubble.ai em { color: var(--cyan); font-style: normal; font-weight: 600; }
.guide-q { display: flex; flex-wrap: wrap; gap: 9px; padding: 16px 22px 22px; border-top: 1px solid var(--stroke); }
.guide-q button { text-align: left; }

/* ---------- FINAL ---------- */
#final { padding: clamp(90px, 14vw, 200px) 20px; text-align: center; position: relative; }
#final .wrap { max-width: 780px; }
#final h2 { font-size: clamp(1.8rem, 5vw, 3rem); font-weight: 700; letter-spacing: -.02em; line-height: 1.12; margin-bottom: 24px;
  background: linear-gradient(180deg, #fff, #9fc2ff); -webkit-background-clip: text; background-clip: text; color: transparent; }
#final p { color: var(--ink-dim); font-size: clamp(1.05rem, 2vw, 1.3rem); line-height: 1.7; }
#final .sig { margin-top: 50px; font-family: var(--font-mono); font-size: 12px; letter-spacing: .2em; color: var(--ink-faint); }

/* ---------- footer ---------- */
.foot { padding: 40px 20px 70px; text-align: center; border-top: 1px solid var(--stroke); color: var(--ink-faint); font-family: var(--font-mono); font-size: 12px; }
.foot a { color: var(--cyan); text-decoration: none; }

/* utility */
.mono { font-family: var(--font-mono); }
.center { text-align: center; }