:root {
  --paper: #f4f2ed;
  --paper-2: #ebe8e1;
  --card: #fbfaf7;
  --ink: #121314;
  --ink-2: #5a5d61;
  --ink-3: #8b8e92;
  --line: rgba(18, 19, 20, 0.12);
  --line-2: rgba(18, 19, 20, 0.22);
  --accent: #ff5a1f;
  --accent-soft: rgba(255, 90, 31, 0.12);
  --pcb: #1b6c40;
  --ok: #1f9d55;
  --glass: rgba(251, 250, 247, 0.86);
  --shadow: 0 1px 2px rgba(0,0,0,.05), 0 12px 40px -12px rgba(0,0,0,.18);
  --sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --r: 14px;
  --gutter: 24px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0e0f10; --paper-2: #161719; --card: #141517;
    --ink: #eceae5; --ink-2: #a3a5a8; --ink-3: #74777b;
    --line: rgba(255,255,255,.1); --line-2: rgba(255,255,255,.2);
    --accent-soft: rgba(255, 90, 31, 0.16);
    --glass: rgba(20, 21, 23, 0.86);
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 16px 48px -12px rgba(0,0,0,.6);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0e0f10; --paper-2: #161719; --card: #141517;
  --ink: #eceae5; --ink-2: #a3a5a8; --ink-3: #74777b;
  --line: rgba(255,255,255,.1); --line-2: rgba(255,255,255,.2);
  --accent-soft: rgba(255, 90, 31, 0.16);
  --glass: rgba(20, 21, 23, 0.86);
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 16px 48px -12px rgba(0,0,0,.6);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 400 16px/1.55 var(--sans); -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; }
h1, h2, h3, h4 { margin: 0; letter-spacing: -0.02em; font-weight: 600; }
p { margin: 0; }
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 var(--gutter); }
.mono { font-family: var(--mono); }
.kicker { font: 500 12px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); }
.kicker b { color: var(--accent); font-weight: 600; }

/* buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px; height: 40px; padding: 0 16px;
  border-radius: 999px; border: 1px solid var(--line-2); background: transparent; color: var(--ink);
  font: 500 14px/1 var(--sans); text-decoration: none; cursor: pointer; white-space: nowrap;
  transition: background .2s, border-color .2s, transform .2s;
}
.btn:hover { border-color: var(--ink); }
.btn.primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn.primary:hover { transform: translateY(-1px); }
.btn.accent { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn.sm { height: 32px; padding: 0 12px; font-size: 13px; }
.btn:focus-visible, .pill:focus-visible, .chip:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* nav */
.nav { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--paper) 82%, transparent); backdrop-filter: blur(14px); border-bottom: 1px solid var(--line); }
.nav .wrap { display: flex; align-items: center; gap: 28px; height: 64px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font: 600 19px/1 var(--sans); letter-spacing: -0.03em; text-decoration: none; }
.logo-mark { width: 22px; height: 22px; border-radius: 6px; background: var(--ink); position: relative; }
.logo-mark::before, .logo-mark::after { content: ""; position: absolute; width: 5px; height: 5px; border-radius: 50%; background: var(--paper); top: 5px; }
.logo-mark::before { left: 5px; } .logo-mark::after { right: 5px; background: var(--accent); }
.logo small { font: 500 12px/1 var(--mono); color: var(--ink-3); letter-spacing: 0; }
.nav-links { display: flex; gap: 22px; margin-left: auto; }
.nav-links a { text-decoration: none; color: var(--ink-2); font-size: 14px; }
.nav-links a:hover { color: var(--ink); }
@media (max-width: 860px) { .nav-links { display: none; } .nav .btn.primary { margin-left: auto; } }

/* hero */
.hero { padding: 56px 0 0; text-align: center; }
.hero h1 { font-size: clamp(40px, 6.4vw, 84px); line-height: .98; letter-spacing: -0.045em; margin: 18px auto 0; max-width: 14ch; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero .lede { color: var(--ink-2); font-size: clamp(16px, 1.6vw, 19px); max-width: 640px; margin: 20px auto 0; }
.hero .cta { display: flex; gap: 10px; justify-content: center; margin-top: 28px; flex-wrap: wrap; }

/* 3D stage */
.stage-wrap { position: relative; margin-top: 24px; }
.stage { position: relative; height: min(72vh, 680px); min-height: 460px; border-radius: 22px; overflow: hidden; touch-action: pan-y;
  background: radial-gradient(70% 60% at 50% 45%, color-mix(in srgb, var(--card) 90%, transparent), transparent 70%); }
.stage canvas { display: block; width: 100%; height: 100%; position: relative; z-index: 0; }
.stage .grid { position: absolute; inset: 0; pointer-events: none; opacity: .55;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px; mask-image: radial-gradient(60% 55% at 50% 55%, #000 30%, transparent 75%); -webkit-mask-image: radial-gradient(60% 55% at 50% 55%, #000 30%, transparent 75%); }
.model-bar { position: absolute; top: 16px; left: 50%; transform: translateX(-50%); z-index: 5; display: flex; gap: 4px; padding: 4px;
  background: var(--glass); border: 1px solid var(--line); border-radius: 999px; backdrop-filter: blur(10px); max-width: calc(100% - 24px); overflow-x: auto; scrollbar-width: none; }
.model-bar::-webkit-scrollbar { display: none; }
.pill { border: 0; background: transparent; color: var(--ink-2); font: 500 13px/1 var(--sans); height: 32px; padding: 0 13px; border-radius: 999px; cursor: pointer; white-space: nowrap; }
.pill:hover { color: var(--ink); }
.pill[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.stage-meta { position: absolute; left: 20px; bottom: 18px; z-index: 4; text-align: left; pointer-events: none; }
.stage-meta .name { font-weight: 600; font-size: 15px; }
.stage-meta .hint { font: 12px/1.4 var(--mono); color: var(--ink-3); margin-top: 4px; }
.stage-tools { position: absolute; right: 16px; bottom: 16px; z-index: 5; display: flex; gap: 6px; }
.icon-btn { height: 34px; padding: 0 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--glass); color: var(--ink); font: 500 12px/1 var(--mono); cursor: pointer; backdrop-filter: blur(10px); }
.icon-btn[aria-pressed="true"] { border-color: var(--accent); color: var(--accent); }
.stage-fallback { position: absolute; inset: 0; display: grid; place-items: center; color: var(--ink-3); font: 13px var(--mono); }

/* leader line + panel */
.leader { position: absolute; inset: 0; pointer-events: none; z-index: 3; overflow: visible; }
.leader line { stroke: var(--accent); stroke-width: 1.2; stroke-dasharray: 3 3; }
.leader circle { fill: var(--accent); }
.leader .ring { fill: none; stroke: var(--accent); stroke-width: 1.2; }
.cpanel { position: absolute; top: 72px; width: 330px; max-height: calc(100% - 140px); overflow: auto; z-index: 6; text-align: left;
  background: var(--glass); backdrop-filter: blur(16px); border: 1px solid var(--line); border-radius: var(--r); box-shadow: var(--shadow);
  padding: 18px; opacity: 0; transform: translateY(6px); pointer-events: none; transition: opacity .2s, transform .2s; }
.cpanel.show { opacity: 1; transform: none; pointer-events: auto; }
.cpanel.right { right: 20px; } .cpanel.left { left: 20px; }
.cpanel .close { position: absolute; top: 10px; right: 10px; width: 26px; height: 26px; border-radius: 50%; border: 0; background: transparent; color: var(--ink-3); cursor: pointer; font-size: 16px; }
.cpanel .close:hover { background: var(--paper-2); color: var(--ink); }
.cpanel h3 { font-size: 22px; margin-top: 8px; }
.cpanel .part { font: 12px var(--mono); color: var(--ink-2); margin-top: 4px; }
.cpanel .app { color: var(--ink-2); font-size: 14px; margin-top: 10px; }
.tabs { display: flex; gap: 2px; margin-top: 14px; border-bottom: 1px solid var(--line); }
.tab { border: 0; background: none; padding: 8px 10px; font: 500 13px var(--sans); color: var(--ink-3); cursor: pointer; border-bottom: 2px solid transparent; margin-bottom: -1px; }
.tab[aria-selected="true"] { color: var(--ink); border-color: var(--accent); }
.tab-body { padding-top: 10px; }
.plist { list-style: none; margin: 0; padding: 0; }
.plist li { padding: 9px 0; border-bottom: 1px solid var(--line); font-size: 14px; }
.plist li:last-child { border-bottom: 0; }
.plist b { font-weight: 600; display: block; }
.plist span { color: var(--ink-2); font-size: 13px; }
.sec-note { display: flex; gap: 10px; font-size: 14px; color: var(--ink-2); padding: 6px 0; }
.sec-note::before { content: ""; flex: 0 0 8px; height: 8px; margin-top: 7px; border-radius: 2px; background: var(--ok); }
.cpanel .btn { margin-top: 14px; width: 100%; justify-content: center; }
@media (max-width: 760px) {
  .cpanel { top: auto; bottom: 62px; left: 10px !important; right: 10px !important; width: auto; max-height: 50%; background: var(--card); backdrop-filter: none; padding: 16px; }
  .leader { display: none; }
  .stage-meta { display: none; }
}

.chips { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; margin: 16px auto 0; max-width: 900px; }
.chip { border: 1px solid var(--line); background: var(--card); color: var(--ink-2); font: 500 12px/1 var(--mono); padding: 8px 10px; border-radius: 999px; cursor: pointer; }
.chip:hover, .chip.on { color: var(--ink); border-color: var(--ink); }
.chip .dot { display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); margin-right: 6px; vertical-align: 1px; }

/* sections */
section { padding: 120px 0 0; }
.sec-head { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: end; margin-bottom: 44px; }
.sec-head h2 { font-size: clamp(30px, 4vw, 52px); line-height: 1.02; letter-spacing: -0.035em; margin-top: 14px; }
.sec-head p { color: var(--ink-2); font-size: 17px; max-width: 520px; }
@media (max-width: 860px) { .sec-head { grid-template-columns: 1fr; gap: 16px; } section { padding-top: 88px; } }

/* how it works */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; background: var(--card); }
.step { padding: 26px 22px; border-right: 1px solid var(--line); min-height: 220px; display: flex; flex-direction: column; }
.step:last-child { border-right: 0; }
.step .n { font: 12px var(--mono); color: var(--accent); }
.step h3 { font-size: 19px; margin: 14px 0 8px; }
.step p { color: var(--ink-2); font-size: 14px; }
.step code { margin-top: auto; padding-top: 16px; font: 12px/1.5 var(--mono); color: var(--ink); display: block; white-space: pre; overflow-x: auto; }
@media (max-width: 860px) { .steps { grid-template-columns: 1fr 1fr; } .step:nth-child(2) { border-right: 0; } .step:nth-child(-n+2) { border-bottom: 1px solid var(--line); } }
@media (max-width: 520px) { .steps { grid-template-columns: 1fr; } .step { border-right: 0; border-bottom: 1px solid var(--line); min-height: 0; } }

.vpl-demo { margin-top: 16px; display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.code { background: #111214; color: #e6e4de; border-radius: var(--r); padding: 20px 22px; font: 13px/1.7 var(--mono); overflow-x: auto; white-space: pre; margin: 0; }
.code .k { color: #ff8a5b; } .code .c { color: #6f747a; } .code .s { color: #9fd8a8; } .code .n { color: #8cc4ff; }
.talk { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 20px; display: flex; flex-direction: column; gap: 10px; }
.bubble { max-width: 88%; padding: 10px 14px; border-radius: 14px; font-size: 14px; }
.bubble.me { align-self: flex-end; background: var(--ink); color: var(--paper); border-bottom-right-radius: 4px; }
.bubble.bot { background: var(--paper-2); border-bottom-left-radius: 4px; }
.bubble .who { display: block; font: 11px var(--mono); color: var(--ink-3); margin-bottom: 3px; }
.bubble.me .who { color: color-mix(in srgb, var(--paper) 60%, transparent); }
@media (max-width: 860px) { .vpl-demo { grid-template-columns: 1fr; } }

/* tree */
.tree { border: 1px solid var(--line); border-radius: 22px; background: var(--card); overflow: hidden; }
.tree-root { display: flex; align-items: center; gap: 14px; padding: 22px 24px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.tree-root .node-root { font: 600 14px var(--mono); padding: 8px 12px; border-radius: 8px; background: var(--ink); color: var(--paper); }
.tree-root p { color: var(--ink-2); font-size: 14px; flex: 1 1 280px; }
.branches { display: grid; grid-template-columns: repeat(5, 1fr); position: relative; }
.branch { text-align: left; border: 0; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); background: transparent; padding: 18px 20px; cursor: pointer; color: var(--ink); position: relative; }
.branch:last-child { border-right: 0; }
.branch .tag { font: 11px var(--mono); color: var(--ink-3); display: block; margin-bottom: 6px; }
.branch .bn { font-weight: 600; font-size: 16px; }
.branch[aria-selected="true"] { background: var(--paper-2); }
.branch[aria-selected="true"]::after { content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; background: var(--accent); }
.branch.core .tag { color: var(--accent); }
@media (max-width: 860px) { .branches { grid-template-columns: 1fr 1fr; } .branch:nth-child(2n) { border-right: 0; } }
.tree-body { padding: 28px 24px 30px; }
.tree-body > p { color: var(--ink-2); max-width: 720px; font-size: 16px; }
.cps { list-style: none; padding: 0; margin: 26px 0 0; display: grid; grid-template-columns: repeat(6, 1fr); gap: 0; position: relative; }
.cps::before { content: ""; position: absolute; left: 12px; right: 12px; top: 12px; height: 1px; background: var(--line-2); }
.cp { position: relative; padding-right: 14px; }
.cp .dot { width: 25px; height: 25px; border-radius: 50%; background: var(--card); border: 1px solid var(--line-2); display: grid; place-items: center; font: 600 10px var(--mono); color: var(--ink-2); position: relative; }
.cp.done .dot { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.cp h4 { font-size: 14px; margin: 12px 0 2px; }
.cp .hint { font: 11px var(--mono); color: var(--ink-3); }
.cp p { font-size: 13px; color: var(--ink-2); margin-top: 8px; }
@media (max-width: 860px) {
  .cps { grid-template-columns: 1fr; gap: 18px; }
  .cps::before { left: 12px; right: auto; top: 12px; bottom: 12px; width: 1px; height: auto; }
  .cp { display: grid; grid-template-columns: 25px 1fr; column-gap: 14px; }
  .cp .dot { grid-row: span 3; } .cp h4 { margin-top: 2px; }
}

/* apps */
.apps-bar { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 18px; }
.apps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.app-card { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; display: flex; flex-direction: column; gap: 10px; transition: border-color .2s, transform .2s; }
.app-card:hover { border-color: var(--line-2); transform: translateY(-2px); }
.app-card .top { display: flex; justify-content: space-between; gap: 10px; align-items: baseline; }
.app-card h4 { font-size: 16px; }
.app-card .br { font: 11px var(--mono); color: var(--ink-3); white-space: nowrap; }
.app-card p { color: var(--ink-2); font-size: 14px; }
.app-card .foot { margin-top: auto; display: flex; justify-content: space-between; align-items: center; gap: 8px; padding-top: 6px; }
.parts { display: flex; gap: 4px; flex-wrap: wrap; }
.parts span { font: 11px var(--mono); padding: 3px 7px; border-radius: 6px; background: var(--paper-2); color: var(--ink-2); }
.meter { display: flex; gap: 3px; } .meter i { width: 10px; height: 4px; border-radius: 2px; background: var(--line-2); }
.meter i.on { background: var(--accent); }
.app-card a { font: 500 13px var(--sans); text-decoration: none; color: var(--accent); white-space: nowrap; }
@media (max-width: 960px) { .apps { grid-template-columns: 1fr 1fr; } }
@media (max-width: 600px) { .apps { grid-template-columns: 1fr; } }

/* security layers */
.layers-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 40px; align-items: center; }
.rings { position: relative; aspect-ratio: 1; max-width: 520px; width: 100%; margin: 0 auto; }
.ring { position: absolute; border-radius: 28px; border: 1px solid var(--line-2); display: flex; justify-content: center; padding-top: 10px; font: 11px var(--mono); color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; transition: border-color .2s, background .2s; }
.ring:nth-child(1) { inset: 0; }
.ring:nth-child(2) { inset: 9%; border-style: dashed; }
.ring:nth-child(3) { inset: 18%; }
.ring:nth-child(4) { inset: 27%; border-style: dashed; }
.ring.core { inset: 36%; background: var(--ink); color: var(--paper); border-color: var(--ink); align-items: center; padding: 0; text-align: center; font-size: 12px; }
.ring.hot { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.layer-list { list-style: none; padding: 0; margin: 0; }
.layer-list li { padding: 16px 0; border-bottom: 1px solid var(--line); display: grid; grid-template-columns: 34px 1fr; gap: 12px; cursor: default; }
.layer-list li .n { font: 12px var(--mono); color: var(--accent); padding-top: 3px; }
.layer-list h4 { font-size: 16px; }
.layer-list p { color: var(--ink-2); font-size: 14px; margin-top: 2px; }
@media (max-width: 860px) { .layers-grid { grid-template-columns: 1fr; } }

/* thesis */
.thesis { padding-top: 140px; }
.thesis blockquote { margin: 0; font-size: clamp(30px, 4.6vw, 60px); line-height: 1.04; letter-spacing: -0.04em; font-weight: 600; max-width: 18ch; }
.thesis blockquote span { color: var(--ink-3); }
.cols3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; margin-top: 52px; border-top: 1px solid var(--line); padding-top: 28px; }
.cols3 h4 { font-size: 17px; margin-bottom: 8px; }
.cols3 p { color: var(--ink-2); font-size: 15px; }
@media (max-width: 860px) { .cols3 { grid-template-columns: 1fr; gap: 22px; } }

/* growth */
.flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.flow .f { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 20px; position: relative; }
.flow .f:not(:last-child)::after { content: "→"; position: absolute; right: -11px; top: 50%; transform: translateY(-50%); width: 20px; height: 20px; border-radius: 50%; background: var(--paper); display: grid; place-items: center; font-size: 12px; color: var(--ink-3); z-index: 1; }
.flow h4 { font-size: 17px; margin: 10px 0 6px; }
.flow p { color: var(--ink-2); font-size: 14px; }
.note { margin-top: 14px; font-size: 13px; color: var(--ink-3); font-family: var(--mono); }
@media (max-width: 860px) { .flow { grid-template-columns: 1fr; } .flow .f:not(:last-child)::after { right: 50%; top: auto; bottom: -11px; transform: translateX(50%) rotate(90deg); } }

/* robots */
.chain { display: grid; grid-template-columns: 1fr auto 1fr auto 1.4fr; gap: 14px; align-items: stretch; }
.chain .col { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; }
.chain .col h4 { font-size: 15px; margin: 8px 0 10px; }
.chain .arrow { align-self: center; color: var(--ink-3); font-size: 20px; }
.chain ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
.chain li { font-size: 14px; color: var(--ink-2); display: flex; gap: 8px; align-items: center; }
.chain li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--line-2); flex: none; }
.chain .col.brain { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.chain .col.brain li { color: color-mix(in srgb, var(--paper) 72%, transparent); }
.chain .col.brain li::before { background: var(--accent); }
.chain .col.brain .kicker { color: color-mix(in srgb, var(--paper) 55%, transparent); }
@media (max-width: 860px) { .chain { grid-template-columns: 1fr; } .chain .arrow { transform: rotate(90deg); justify-self: center; } }

/* pricing */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.plan { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 24px; display: flex; flex-direction: column; gap: 12px; }
.plan.hl { border-color: var(--ink); box-shadow: var(--shadow); }
.plan .price { font-size: 38px; font-weight: 600; letter-spacing: -0.03em; }
.plan .price small { font-size: 14px; color: var(--ink-3); font-weight: 400; letter-spacing: 0; }
.plan ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; color: var(--ink-2); font-size: 14px; }
.plan ul li::before { content: "✓  "; color: var(--ok); }
.plan .btn { margin-top: auto; justify-content: center; }
@media (max-width: 860px) { .plans { grid-template-columns: 1fr; } }

/* final cta + footer */
.final { margin: 120px auto 0; text-align: center; padding: 72px 24px; border-radius: 28px; background: var(--ink); color: var(--paper); }
.final h2 { font-size: clamp(32px, 5vw, 64px); letter-spacing: -0.04em; line-height: 1; }
.final p { color: color-mix(in srgb, var(--paper) 65%, transparent); margin: 16px auto 28px; max-width: 520px; }
.final .btn.primary { background: var(--paper); color: var(--ink); border-color: var(--paper); }
footer { padding: 40px 0 48px; color: var(--ink-3); font-size: 13px; }
footer .wrap { display: flex; gap: 20px; justify-content: space-between; flex-wrap: wrap; }

@media (max-width: 600px) { :root { --gutter: 16px; } .stage { min-height: 0; height: 470px; border-radius: 16px; } }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }