:root {
  --bg: #ffffff;
  --warm: #f5f3ee;
  --ink: #121211;
  --ink-2: #3b3a37;
  --mute: #6c6963;
  --faint: #a29e96;
  --line: #e2dfd8;
  --line-2: #cfcbc2;
  --card: #ffffff;
  --code-bg: #141413;
  --code-fg: #ecebe6;
  --code-dim: #8d8a83;
  --code-line: #2a2a28;
  --sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --radius: 14px;
  --gutter: 24px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0e0d;
    --warm: #151514;
    --ink: #f0eee9;
    --ink-2: #cdcac3;
    --mute: #95918a;
    --faint: #64615c;
    --line: #262624;
    --line-2: #3a3936;
    --card: #121211;
    --code-bg: #090908;
    --code-fg: #ecebe6;
    --code-dim: #85827b;
    --code-line: #262624;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 76px; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  font-feature-settings: "cv11", "ss01";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg { max-width: 100%; }
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; border-radius: 4px; }

code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--warm);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.08em 0.36em;
  white-space: nowrap;
}
code.wrapcode { white-space: normal; overflow-wrap: anywhere; }
.section-warm code { background: var(--bg); }

q { quotes: "\201C" "\201D"; font-style: italic; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 var(--gutter); }

.skip { position: absolute; left: -9999px; top: 8px; background: var(--ink); color: var(--bg); padding: 8px 12px; border-radius: 8px; z-index: 50; }
.skip:focus { left: 8px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-row { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 650; font-size: 18px; letter-spacing: -0.01em; text-decoration: none; }
.mark { width: 26px; height: 26px; flex: none; }
.mark rect { fill: var(--ink); }
.mark path { fill: none; stroke: var(--bg); stroke-width: 3.4; stroke-linejoin: round; }
.nav-links { display: flex; align-items: center; gap: 26px; font-size: 15px; }
.nav-links a { text-decoration: none; color: var(--mute); }
.nav-links a:hover { color: var(--ink); }
.nav-links .nav-gh { color: var(--ink); border: 1px solid var(--line-2); border-radius: 999px; padding: 5px 14px; }
.nav-links .nav-gh:hover { border-color: var(--ink); }

/* Hero */
.hero { padding: clamp(64px, 11vw, 128px) 0 clamp(48px, 7vw, 80px); }
.eyebrow, .kicker {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--mute);
  margin: 0 0 22px;
}
h1 {
  font-size: clamp(38px, 6.4vw, 78px);
  line-height: 1.02;
  letter-spacing: -0.035em;
  font-weight: 650;
  margin: 0;
  max-width: 17ch;
  text-wrap: balance;
}
h1 > span { display: block; color: var(--faint); }
.nw { white-space: nowrap; }
.lede {
  font-size: clamp(18px, 1.6vw, 21px);
  line-height: 1.55;
  color: var(--ink-2);
  max-width: 40em;
  margin: 32px 0 0;
}
.cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 46px; padding: 0 22px;
  border-radius: 999px;
  font-size: 16px; font-weight: 550;
  text-decoration: none;
  transition: background-color .15s, border-color .15s, color .15s;
}
.btn-solid { background: var(--ink); color: var(--bg); border: 1px solid var(--ink); }
.btn-solid:hover { background: var(--ink-2); border-color: var(--ink-2); }
.btn-line { border: 1px solid var(--line-2); color: var(--ink); }
.btn-line:hover { border-color: var(--ink); }

.install {
  display: inline-flex; align-items: center; gap: 12px;
  margin-top: 28px;
  max-width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 8px 8px 8px 16px;
  background: var(--warm);
}
.install code { flex: 1 1 auto; min-width: 0; background: none; border: 0; padding: 0; font-size: 15px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.install .prompt { color: var(--faint); margin-right: 6px; user-select: none; }
.meta { margin: 16px 0 0; font-size: 14px; color: var(--mute); }

/* Copy buttons */
.copy {
  font: 500 13px/1 var(--sans);
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--line-2);
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
  flex: none;
  transition: border-color .15s, background-color .15s;
}
.copy:hover { border-color: var(--ink); }
.copy.is-done { background: var(--ink); color: var(--bg); border-color: var(--ink); }

/* Diagram */
.diagram-band { padding: 0 0 clamp(56px, 8vw, 96px); }
.diagram {
  margin: 0;
  background: var(--warm);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: clamp(20px, 4vw, 48px);
}
.dg { display: block; width: 100%; height: auto; overflow: visible; }
.dg-tall { display: none; max-width: 380px; margin: 0 auto; }
.dg-box { fill: var(--card); stroke: var(--line-2); stroke-width: 1.2; }
.dg-relay { fill: var(--ink); stroke: var(--ink); }
.dg-label { font: 600 12px var(--mono); letter-spacing: 0.08em; fill: var(--mute); }
.dg-mono { font: 400 15px var(--mono); fill: var(--ink-2); }
.dg-strong { font-weight: 600; fill: var(--ink); }
.dg-faint { fill: var(--faint); }
.dg-small { font: 400 13px var(--sans); fill: var(--mute); }
.dg-center { text-anchor: middle; }
.dg-cipher { fill: var(--bg); opacity: 0.78; font-size: 14px; }
.dg-on-ink { fill: var(--bg); opacity: 0.6; }
.dg-rule { stroke: var(--line); stroke-width: 1; }
.dg-key { fill: none; stroke: var(--ink); stroke-width: 1.8; stroke-linecap: round; }
.dg-link { stroke: var(--ink); stroke-width: 1.6; }
.dg-head { fill: var(--ink); }
.dg-tag { font: 500 12px var(--mono); fill: var(--mute); letter-spacing: 0.02em; }
.diagram figcaption { margin-top: clamp(16px, 3vw, 28px); text-align: center; color: var(--mute); font-size: 15px; }

/* Sections */
.section { padding: clamp(72px, 10vw, 128px) 0; border-top: 1px solid var(--line); }
.section-warm { background: var(--warm); }
h2 {
  font-size: clamp(30px, 3.8vw, 46px);
  line-height: 1.08;
  letter-spacing: -0.028em;
  font-weight: 650;
  margin: 0;
  text-wrap: balance;
}
h3 { font-size: 18px; line-height: 1.3; letter-spacing: -0.01em; font-weight: 620; margin: 0; }
.sub { font-size: 20px; margin: 0 0 18px; }
.split { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: 32px 64px; align-items: start; }
.split-tight { margin-top: 72px; align-items: center; }
.prose p { margin: 0 0 1em; color: var(--ink-2); }
.prose p:last-child { margin-bottom: 0; }
.prose > .sub { margin-top: 0; }

/* Features */
.features {
  list-style: none; padding: 0; margin: clamp(48px, 7vw, 80px) 0 0;
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
}
.features li { padding: 28px 28px 32px 0; border-bottom: 1px solid var(--line); }
.features li:not(:nth-child(3n+1)) { padding-left: 28px; border-left: 1px solid var(--line); }
.features h3 { margin-bottom: 10px; }
.features p { margin: 0; color: var(--mute); font-size: 15.5px; }

/* Demo */
.demo { margin: 40px 0 0; }
.demo img {
  display: block; width: 100%; height: auto;
  border-radius: 14px;
  background: #141414;
  border: 1px solid var(--line-2);
  box-shadow: 0 1px 0 rgba(0,0,0,.02), 0 24px 60px -30px rgba(0,0,0,.35);
}
.demo figcaption { margin-top: 16px; color: var(--mute); font-size: 15px; max-width: 46em; }

/* Steps + code */
.steps { list-style: none; padding: 0; margin: 56px 0 0; display: grid; grid-template-columns: minmax(0, 1fr); gap: 40px; }
.steps > li { min-width: 0; }
.step-head { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.step-n {
  width: 30px; height: 30px; flex: none;
  display: inline-grid; place-items: center;
  border: 1px solid var(--ink); border-radius: 999px;
  font: 600 14px var(--mono);
}
.code {
  position: relative;
  background: var(--code-bg);
  color: var(--code-fg);
  border: 1px solid var(--code-line);
  border-radius: var(--radius);
}
.code pre { margin: 0; padding: 20px 22px; overflow-x: auto; font: 14.5px/1.7 var(--mono); }
.code pre code { white-space: pre; background: none; border: 0; padding: 0; font-size: inherit; overflow-wrap: normal; color: inherit; }
.code .c { color: var(--code-dim); }
.code .copy {
  position: absolute; top: 12px; right: 12px;
  background: #23231f; color: #ecebe6; border-color: #3a3a36;
}
.code .copy:hover { border-color: #8d8a83; }
.code .copy.is-done { background: #ecebe6; color: #141413; border-color: #ecebe6; }
.code pre { padding-right: 88px; }
.note { margin: 12px 0 0; font-size: 15px; color: var(--mute); }

/* Derivation */
.derive { margin-top: 56px; }
.secret {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 16px;
  background: var(--ink); color: var(--bg);
  border-radius: var(--radius);
  padding: 18px 22px;
}
.secret-label { font: 600 13px var(--mono); letter-spacing: 0.08em; text-transform: uppercase; }
.secret-val { font: 15px var(--mono); opacity: 0.75; }
.derive-grid {
  position: relative;
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px;
  padding-top: 32px;
}
.dcard {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}
.dcard::before { content: ""; position: absolute; top: -33px; left: 50%; width: 1px; height: 32px; background: var(--mute); }
.dcard-strong { border-color: var(--ink); }
.dname { margin: 0 0 10px; font-weight: 620; font-size: 18px; letter-spacing: -0.01em; }
.dformula {
  display: block;
  background: var(--warm) !important;
  font-size: 13px !important;
  padding: 10px 12px !important;
  border-radius: 8px !important;
  line-height: 1.5;
  white-space: normal;
  overflow-wrap: anywhere;
}
.dwho { margin: 14px 0 10px; }
.dcard > p:last-child { margin: 0; color: var(--mute); font-size: 15px; }
.pill {
  display: inline-block;
  font: 500 12px var(--mono);
  letter-spacing: 0.02em;
  border: 1px solid var(--line-2);
  border-radius: 999px;
  padding: 3px 10px;
  color: var(--ink-2);
}
.pill-solid { background: var(--ink); color: var(--bg); border-color: var(--ink); }

.derive + .sub { margin-top: 72px; }
.flow { list-style: none; padding: 0; margin: 0; display: grid; gap: 0; border-top: 1px solid var(--line-2); }
.flow li { display: grid; grid-template-columns: 48px minmax(0, 1fr); gap: 8px; padding: 20px 0; border-bottom: 1px solid var(--line-2); }
.flow-n { font: 600 14px var(--mono); color: var(--mute); padding-top: 2px; }
.flow p { margin: 0; color: var(--ink-2); max-width: 52em; }

.tools { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 32px 64px; margin-top: 72px; }
.defs { margin: 0; display: grid; grid-template-columns: max-content minmax(0, 1fr); gap: 0; border-top: 1px solid var(--line-2); }
.defs dt, .defs dd { padding: 11px 0; border-bottom: 1px solid var(--line-2); margin: 0; font-size: 15px; }
.defs dt code { font-size: 13.5px; }
.defs dt { padding-right: 20px; }
.defs dd { color: var(--mute); }

/* Security */
.sec-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 56px; }
.sec-card { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; background: var(--card); }
.sec-card h3 { margin-bottom: 16px; }
.sec-card p { margin: 0; font-size: 15.5px; padding-left: 22px; position: relative; }
.sec-card p + p { margin-top: 12px; }
.sec-yes { color: var(--ink-2); }
.sec-no { color: var(--mute); }
.sec-yes::before, .sec-no::before { position: absolute; left: 0; top: 0; font: 600 14px var(--mono); }
.sec-yes::before { content: "+"; color: var(--ink); }
.sec-no::before { content: "\2212"; color: var(--faint); }
.facts { list-style: none; padding: 0; margin: 24px 0 0; }
.facts li { padding: 12px 0; border-top: 1px solid var(--line); color: var(--ink-2); font-size: 15.5px; }
.facts strong { color: var(--ink); font-weight: 620; }
.code-banner pre { padding: 22px; font-size: 12.5px; line-height: 1.65; }

/* Roadmap */
.roadmap { list-style: none; padding: 0; margin: 48px 0 0; border-top: 1px solid var(--line-2); }
.roadmap li { display: flex; align-items: baseline; gap: 18px; padding: 16px 0; border-bottom: 1px solid var(--line-2); color: var(--ink-2); }
.tag {
  flex: none;
  font: 500 11.5px var(--mono); letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--mute);
  border: 1px dashed var(--faint);
  border-radius: 999px;
  padding: 2px 10px;
  position: relative; top: -1px;
}

/* Footer */
.foot { border-top: 1px solid var(--line); padding: 40px 0 56px; }
.foot-row { display: flex; flex-wrap: wrap; align-items: center; gap: 16px 32px; }
.foot-row p { margin: 0; color: var(--mute); font-size: 15px; flex: 1 1 280px; }
.foot-links { display: flex; flex-wrap: wrap; gap: 8px 24px; font-size: 15px; }
.foot-links a { color: var(--mute); text-decoration: none; }
.foot-links a:hover { color: var(--ink); text-decoration: underline; }

/* Responsive */
@media (max-width: 960px) {
  .features { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .features li:not(:nth-child(3n+1)) { padding-left: 0; border-left: 0; }
  .features li { padding: 28px 24px 30px 0; }
  .features li:nth-child(2n) { padding-left: 24px; border-left: 1px solid var(--line); padding-right: 0; }
  .sec-grid { grid-template-columns: minmax(0, 1fr); }
  .split { grid-template-columns: minmax(0, 1fr); gap: 20px; }
  .split-tight { margin-top: 56px; }
  .tools { grid-template-columns: minmax(0, 1fr); gap: 48px; }
}

@media (max-width: 760px) {
  :root { --gutter: 16px; }
  body { font-size: 16px; }
  .nav-links a:not(.nav-gh) { display: none; }
  .dg-wide { display: none; }
  .dg-tall { display: block; }
  .derive-grid { grid-template-columns: minmax(0, 1fr); padding-top: 16px; gap: 12px; }
  .derive-grid::before, .derive-grid::after { display: none; }
  .dcard::before { display: none; }
  .features { grid-template-columns: minmax(0, 1fr); }
  .features li, .features li:nth-child(2n) { padding: 24px 0; border-left: 0; }
  .defs { grid-template-columns: minmax(0, 1fr); }
  .defs dt { border-bottom: 0; padding-bottom: 2px; }
  .defs dd { padding-top: 0; }
  .roadmap li { flex-direction: column; gap: 8px; }
  .flow li { grid-template-columns: 32px minmax(0, 1fr); }
  .code pre { font-size: 13px; padding: 52px 16px 18px; }
  .code-banner pre { padding-top: 18px; font-size: 11.5px; }
  .install { display: flex; }
  .install code { font-size: 14px; }
  .btn { flex: 1 1 auto; }
}

@media (max-width: 400px) {
  .install { padding-left: 12px; gap: 8px; }
  .install code { font-size: 13px; }
  .install .prompt { margin-right: 4px; }
}