:root {
  color-scheme: dark;

  --ink: #F1F5FB;
  --ink-2: #B3BED2;
  --muted: #7C89A3;
  --bg: #060A13;
  --bg-alt: #0A101D;
  --surface: #0F1728;
  --surface-2: #142039;
  --line: #1E2A45;
  --line-2: #2A3A5E;

  --accent: #3FF0C6;
  --accent-2: #36C8FF;
  --accent-ink: #7AF7D9;
  --accent-soft: rgba(63, 240, 198, .12);
  --violet: #9D8CFF;
  --violet-soft: rgba(157, 140, 255, .14);
  --mint: #3FF0C6;
  --warn: #FF8A65;
  --on-accent: #04130F;

  --grad: linear-gradient(120deg, var(--accent) 0%, var(--accent-2) 55%, var(--violet) 100%);

  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 0 rgba(255, 255, 255, .04) inset, 0 24px 60px -24px rgba(0, 0, 0, .7);
  --glow: 0 0 0 1px rgba(63, 240, 198, .25), 0 20px 60px -20px rgba(63, 240, 198, .35);

  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --serif: "Instrument Serif", Georgia, serif;
  --mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Consolas, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html { scroll-behavior: smooth; scroll-padding-top: 80px; background: var(--bg); }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: rgba(63, 240, 198, .3); color: #fff; }

h1, h2, h3 { line-height: 1.15; margin: 0; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.9rem, 3.4vw, 2.75rem); font-weight: 600; }
h3 { font-size: 1.05rem; font-weight: 600; letter-spacing: -0.01em; }
p { margin: 0; }
em { font-family: var(--serif); font-style: italic; font-weight: 400; letter-spacing: -0.01em; }
code { font-family: var(--mono); font-size: .88em; }
a { color: inherit; }

.grad-text, h1 em, .vision h2 em {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
  padding-right: .06em;
}

.wrap { width: min(1160px, 100% - 40px); margin-inline: auto; }

.skip {
  position: absolute; left: 12px; top: -48px; z-index: 100;
  background: var(--accent); color: var(--on-accent); padding: 8px 14px; border-radius: 8px;
}
.skip:focus { top: 12px; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 22px;
  border-radius: 999px;
  background: var(--grad); color: var(--on-accent);
  font: 600 15px/1 var(--sans);
  text-decoration: none; border: 0;
  cursor: pointer;
  box-shadow: 0 10px 30px -12px rgba(63, 240, 198, .6);
  transition: transform .15s ease, box-shadow .15s ease, filter .15s ease;
}
.btn:hover { transform: translateY(-1px); filter: brightness(1.08); box-shadow: 0 14px 36px -12px rgba(54, 200, 255, .7); }
.btn-sm { padding: 9px 16px; font-size: 14px; }
.btn-ghost { background: rgba(255, 255, 255, .03); color: var(--ink); border: 1px solid var(--line-2); box-shadow: none; }
.btn-ghost:hover { background: rgba(255, 255, 255, .07); box-shadow: none; filter: none; }
.btn-block { width: 100%; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(6, 10, 19, .72);
  backdrop-filter: saturate(1.6) blur(14px);
  -webkit-backdrop-filter: saturate(1.6) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}
.nav.scrolled { border-bottom-color: var(--line); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }

.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; letter-spacing: -0.02em; text-decoration: none; color: var(--ink); }
.mark { width: 28px; height: 28px; color: var(--surface-2); filter: drop-shadow(0 0 10px rgba(63, 240, 198, .35)); }

.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a:not(.btn) { text-decoration: none; font-size: 15px; color: var(--ink-2); font-weight: 500; transition: color .15s ease; }
.nav-links a:not(.btn):hover { color: var(--accent); }

.nav-toggle { display: none; background: none; border: 0; padding: 10px; cursor: pointer; }
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--ink); margin: 5px 0; border-radius: 2px; transition: transform .2s ease; }
.nav-toggle[aria-expanded="true"] span:first-child { transform: translateY(3.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:last-child { transform: translateY(-3.5px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 96px 0 120px;
  overflow: hidden;
  isolation: isolate;
}
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(600px 420px at 78% 30%, rgba(63, 240, 198, .22), transparent 70%),
    radial-gradient(520px 380px at 95% 80%, rgba(157, 140, 255, .22), transparent 70%),
    radial-gradient(480px 360px at 10% 0%, rgba(54, 200, 255, .12), transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background-image:
    linear-gradient(rgba(255, 255, 255, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .035) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse at 60% 40%, #000 20%, transparent 75%);
  mask-image: radial-gradient(ellipse at 60% 40%, #000 20%, transparent 75%);
  pointer-events: none;
}
.hero-grid { position: relative; display: grid; grid-template-columns: 1.3fr .8fr; gap: 56px; align-items: center; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 6px 14px 6px 10px; border-radius: 999px;
  background: rgba(63, 240, 198, .07); border: 1px solid rgba(63, 240, 198, .28);
  font-size: 13.5px; font-weight: 500; color: var(--accent-ink);
  margin-bottom: 28px;
}
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(63, 240, 198, .18), 0 0 12px var(--accent); animation: pulse 2.4s ease-in-out infinite; }
@keyframes pulse { 50% { box-shadow: 0 0 0 7px rgba(63, 240, 198, 0), 0 0 16px var(--accent); } }
@media (prefers-reduced-motion: reduce) { .dot { animation: none; } }

h1 { font-size: clamp(2.5rem, 5.2vw, 4.4rem); font-weight: 600; letter-spacing: -0.035em; line-height: 1.02; }
h1 em { font-size: 1.06em; }

.lede { font-size: clamp(1.08rem, 1.5vw, 1.25rem); color: var(--ink-2); max-width: 34em; margin-top: 26px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }

/* receipt card */
.receipt {
  position: relative;
  background: linear-gradient(180deg, rgba(20, 32, 57, .9), rgba(15, 23, 40, .9));
  border: 1px solid var(--line-2);
  border-radius: 20px;
  padding: 24px;
  box-shadow: var(--shadow), 0 0 80px -20px rgba(63, 240, 198, .35);
  max-width: 420px; margin-left: auto;
  backdrop-filter: blur(8px);
}
.receipt::before {
  content: ""; position: absolute; inset: -1px; border-radius: 21px; padding: 1px;
  background: linear-gradient(140deg, rgba(63, 240, 198, .7), transparent 40%, transparent 60%, rgba(157, 140, 255, .7));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude;
  pointer-events: none;
}
.receipt-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; }
.receipt-title { font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.pill { font-size: 12.5px; font-weight: 600; padding: 4px 10px; border-radius: 999px; }
.pill-ok { background: var(--accent-soft); color: var(--accent); border: 1px solid rgba(63, 240, 198, .3); }
.pill-ok::before { content: "✓ "; }

.claims { margin: 0; font-family: var(--mono); font-size: 14.5px; background: rgba(6, 10, 19, .7); border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 14px 16px; }
.claims div { display: flex; justify-content: space-between; gap: 16px; padding: 5px 0; }
.claims dt { color: var(--ink-2); }
.claims dd { margin: 0; text-align: right; }
.v-true { color: var(--accent); font-weight: 500; text-shadow: 0 0 12px rgba(63, 240, 198, .5); }
.v-str { color: #FFC978; }

.receipt-divider { display: flex; align-items: center; gap: 12px; margin: 22px 0 14px; font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.receipt-divider::before, .receipt-divider::after { content: ""; flex: 1; height: 1px; background: var(--line); }

.withheld { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 8px 16px; }
.withheld li { font-size: 14px; color: var(--muted); display: flex; align-items: center; gap: 8px; text-decoration: line-through; text-decoration-color: rgba(255, 138, 101, .55); }
.withheld li::before {
  content: ""; flex: none; width: 14px; height: 14px; border-radius: 4px;
  background: repeating-linear-gradient(135deg, var(--line-2) 0 3px, transparent 3px 6px);
  border: 1px solid var(--line-2);
}

/* ---------- Sections ---------- */
.section { padding: 112px 0; position: relative; }
.section-alt { background: var(--bg-alt); border-block: 1px solid var(--line); }
.section-head { max-width: 760px; margin-bottom: 56px; }
.kicker { font-size: 13px; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); margin-bottom: 16px; display: flex; align-items: center; gap: 10px; }
.kicker::before { content: ""; width: 18px; height: 2px; border-radius: 2px; background: var(--grad); }
.sub { font-size: 1.1rem; color: var(--ink-2); margin-top: 18px; max-width: 40em; }

.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 32px; }
.card h3 { font-size: 1.2rem; margin-bottom: 18px; }
.card p + p { margin-top: 14px; }
.card p { color: var(--ink-2); }
.card-tint {
  background:
    radial-gradient(420px 260px at 100% 100%, rgba(63, 240, 198, .12), transparent 70%),
    var(--surface);
  border-color: rgba(63, 240, 198, .22);
}

.problem-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }

.ticks { list-style: none; margin: 0; padding: 0; }
.ticks li { position: relative; padding: 10px 0 10px 28px; border-top: 1px solid var(--line); color: var(--ink-2); }
.ticks li:first-child { border-top: 0; padding-top: 0; }
.ticks li::before { content: ""; position: absolute; left: 4px; top: 19px; width: 8px; height: 8px; border-radius: 50%; background: var(--warn); box-shadow: 0 0 10px rgba(255, 138, 101, .6); }
.ticks li:first-child::before { top: 9px; }
.ticks strong { color: var(--ink); font-weight: 600; }

.callout { margin-top: 22px !important; padding: 16px 18px; border-left: 3px solid var(--accent); background: rgba(63, 240, 198, .06); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; color: var(--ink) !important; }
.callout strong { color: var(--accent-ink); }

/* ---------- Flow ---------- */
.flow { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; position: relative; }
.flow-node {
  position: relative;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 20px 24px;
  transition: border-color .2s ease, transform .2s ease;
}
.flow-node:hover { border-color: var(--line-2); transform: translateY(-2px); }
.flow-node:not(:last-child)::after {
  content: ""; position: absolute; top: 46px; right: -13px; z-index: 1;
  width: 10px; height: 10px;
  border-top: 2px solid var(--accent); border-right: 2px solid var(--accent);
  transform: rotate(45deg);
  filter: drop-shadow(0 0 4px var(--accent));
}
.flow-node-hp {
  background:
    radial-gradient(240px 180px at 50% 0%, rgba(63, 240, 198, .22), transparent 70%),
    var(--surface-2);
  border-color: rgba(63, 240, 198, .55);
  box-shadow: var(--glow);
}
.flow-node-hp .flow-icon { background: var(--grad); color: var(--on-accent); box-shadow: 0 0 24px rgba(63, 240, 198, .5); }
.flow-node-hp .flow-num { color: var(--accent); }
.flow-num { position: absolute; top: 16px; right: 18px; font-family: var(--mono); font-size: 12px; color: var(--muted); }
.flow-icon { width: 48px; height: 48px; border-radius: 12px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; margin-bottom: 18px; border: 1px solid rgba(63, 240, 198, .18); }
.flow-node:nth-child(2) .flow-icon, .flow-node:nth-child(4) .flow-icon { background: var(--violet-soft); color: var(--violet); border-color: rgba(157, 140, 255, .22); }
.flow-icon svg { width: 26px; height: 26px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.flow-icon svg .fill { fill: currentColor; }
.flow-node h3 { font-size: 1rem; margin-bottom: 8px; }
.flow-node p { font-size: 14.5px; color: var(--ink-2); line-height: 1.5; }
.flow-node code { color: var(--accent-ink); }

.table-wrap { margin-top: 48px; overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--line); background: var(--surface); }
.who-sees { width: 100%; border-collapse: collapse; font-size: 15px; min-width: 640px; }
.who-sees caption { text-align: left; padding: 20px 24px 4px; font-weight: 600; font-size: 1.05rem; }
.who-sees th, .who-sees td { padding: 16px 24px; text-align: left; border-top: 1px solid var(--line); }
.who-sees thead th { font-size: 13px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); font-weight: 600; border-top: 0; }
.who-sees tbody th { font-weight: 500; color: var(--ink); }
.who-sees tbody tr:hover { background: rgba(255, 255, 255, .02); }
.yes, .no, .min { display: inline-flex; align-items: center; gap: 8px; font-weight: 500; }
.yes::before, .no::before, .min::before { content: ""; width: 8px; height: 8px; border-radius: 50%; }
.yes { color: var(--accent); } .yes::before { background: var(--accent); box-shadow: 0 0 8px var(--accent); }
.no { color: var(--ink-2); } .no::before { background: transparent; border: 2px solid var(--muted); width: 6px; height: 6px; }
.min { color: #C5BDFF; } .min::before { background: var(--violet); box-shadow: 0 0 8px var(--violet); }

/* ---------- Privacy ---------- */
.privacy-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 72px; align-items: center; }
.principles { list-style: none; margin: 40px 0 0; padding: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 28px 32px; }
.principles li { padding-top: 18px; border-top: 2px solid; border-image: var(--grad) 1; }
.principles h3 { margin-bottom: 6px; }
.principles p { font-size: 15px; color: var(--ink-2); }

.pairwise {
  margin: 0;
  background:
    radial-gradient(360px 260px at 20% 50%, rgba(63, 240, 198, .12), transparent 70%),
    radial-gradient(300px 260px at 90% 50%, rgba(157, 140, 255, .12), transparent 70%),
    var(--surface);
  border: 1px solid var(--line-2); border-radius: 20px; padding: 28px; box-shadow: var(--shadow);
}
.pairwise svg { width: 100%; height: auto; display: block; overflow: visible; }
.pw-line { fill: none; stroke: url(#g-line); stroke-width: 2; stroke-dasharray: 4 5; animation: dash 18s linear infinite; }
@keyframes dash { to { stroke-dashoffset: -180; } }
@media (prefers-reduced-motion: reduce) { .pw-line { animation: none; } }
.pw-person circle:first-child { fill: rgba(63, 240, 198, .14); stroke: var(--accent); stroke-width: 1.5; filter: drop-shadow(0 0 10px rgba(63, 240, 198, .6)); }
.pw-ink { fill: var(--accent); }
.pw-ink-stroke { fill: none; stroke: var(--accent); stroke-width: 3; stroke-linecap: round; }
.pw-label { font: 500 13px var(--sans); fill: var(--ink-2); }
.pw-site rect { fill: var(--bg); stroke: var(--line-2); }
.pw-host { font: 600 13px var(--sans); fill: var(--ink); }
.pw-id { font: 500 13px var(--mono); fill: var(--accent); }
/* g:nth-of-type(1) is the person; sites are 2–4 */
.pw-site:nth-of-type(3) .pw-id { fill: var(--accent-2); }
.pw-site:nth-of-type(4) .pw-id { fill: var(--violet); }
.pairwise figcaption { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 14.5px; color: var(--ink-2); }
.pairwise figcaption strong { display: block; color: var(--ink); margin-bottom: 4px; }
.pairwise figcaption code { color: var(--accent); }

/* ---------- Platforms ---------- */
.benefits { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.benefit { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; transition: border-color .2s ease, transform .2s ease, box-shadow .2s ease; }
.benefit:hover { border-color: rgba(63, 240, 198, .4); transform: translateY(-3px); box-shadow: 0 20px 40px -24px rgba(63, 240, 198, .45); }
.benefit h3 { margin-bottom: 10px; }
.benefit p { font-size: 15px; color: var(--ink-2); }
.benefit::before { content: ""; display: block; width: 32px; height: 3px; background: var(--grad); border-radius: 2px; margin-bottom: 20px; box-shadow: 0 0 12px rgba(63, 240, 198, .5); }

.use-cases { margin-top: 56px; display: flex; flex-wrap: wrap; align-items: center; gap: 16px 24px; }
.use-cases-label { font-size: 14px; font-weight: 600; color: var(--muted); }
.use-cases ul { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 10px; }
.use-cases li { padding: 7px 14px; border-radius: 999px; border: 1px solid var(--line-2); background: var(--surface); font-size: 14px; font-weight: 500; color: var(--ink-2); }

/* ---------- Developers ---------- */
.section-dark {
  background:
    radial-gradient(700px 400px at 85% 50%, rgba(157, 140, 255, .14), transparent 70%),
    radial-gradient(500px 300px at 0% 100%, rgba(63, 240, 198, .08), transparent 70%),
    #04070E;
  border-block: 1px solid var(--line);
}
.kicker-dark { color: var(--violet); }
.kicker-dark::before { background: var(--violet); }
.tag { font-size: 11px; letter-spacing: .06em; padding: 3px 8px; border-radius: 6px; border: 1px solid rgba(157, 140, 255, .35); color: #C5BDFF; background: var(--violet-soft); }
.dev-grid { display: grid; grid-template-columns: 1fr 1.05fr; gap: 64px; align-items: center; }
.dev-grid > *, .hero-grid > *, .privacy-grid > *, .contact-grid > * { min-width: 0; }
.steps { list-style: none; margin: 36px 0 0; padding: 0; }
.steps li { display: flex; gap: 16px; padding: 14px 0; border-top: 1px solid var(--line); color: var(--ink-2); font-size: 15.5px; }
.steps li p { min-width: 0; overflow-wrap: anywhere; }
.steps li span { font-family: var(--mono); font-size: 13px; color: var(--violet); padding-top: 2px; }
.steps code { color: var(--accent-ink); background: var(--surface); padding: 2px 6px; border-radius: 5px; border: 1px solid var(--line); }
.fine { margin-top: 24px; font-size: 13px; color: var(--muted); }

.code-card { position: relative; background: var(--surface); border: 1px solid var(--line-2); border-radius: 18px; overflow: hidden; box-shadow: 0 30px 80px -30px rgba(0, 0, 0, .9), 0 0 100px -30px rgba(157, 140, 255, .45); }
.code-card::before { content: ""; position: absolute; top: 0; left: 0; right: 0; height: 1px; background: var(--grad); opacity: .8; }
.code-tabs { display: flex; gap: 4px; padding: 10px 10px 0; border-bottom: 1px solid var(--line); }
.code-tabs button {
  background: none; border: 0; color: var(--muted); font: 500 13px var(--mono);
  padding: 10px 14px; border-radius: 8px 8px 0 0; cursor: pointer; position: relative;
}
.code-tabs button:hover { color: var(--ink-2); }
.code-tabs button[aria-selected="true"] { color: #fff; background: #070B15; }
.code-tabs button[aria-selected="true"]::after { content: ""; position: absolute; left: 14px; right: 14px; bottom: -1px; height: 2px; background: var(--grad); }
.code-card pre { margin: 0; padding: 24px 26px 28px; background: #070B15; overflow-x: auto; font: 14px/1.75 var(--mono); color: #DCE3EE; min-height: 300px; }
.code-card code { font-size: inherit; }
.c { color: #5E6B86; } .k { color: #3FF0C6; } .s { color: #FFC978; } .b { color: #5CC8FF; } .n { color: #B9A8FF; }

/* ---------- Vision ---------- */
.vision h2 { max-width: 20em; }
.vision-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 48px; margin-top: 56px; }
.vision-grid h3 { font-size: 1.15rem; margin-bottom: 10px; }
.vision-grid p { color: var(--ink-2); font-size: 15.5px; }
.vision-grid > div { padding-top: 22px; border-top: 1px solid var(--line-2); position: relative; }
.vision-grid > div::before { content: ""; position: absolute; top: -1px; left: 0; width: 56px; height: 2px; background: var(--grad); box-shadow: 0 0 12px rgba(63, 240, 198, .6); }

/* ---------- Contact ---------- */
#contact {
  background:
    radial-gradient(600px 400px at 90% 20%, rgba(63, 240, 198, .10), transparent 70%),
    var(--bg-alt);
}
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 72px; align-items: start; }
.audience { margin-top: 36px; display: grid; gap: 20px; }
.audience > div { padding-left: 18px; border-left: 2px solid var(--accent); }
.audience > div:last-child { border-left-color: var(--violet); }
.audience h3 { margin-bottom: 4px; }
.audience p { color: var(--ink-2); font-size: 15px; }

.contact-form { background: var(--surface); border: 1px solid var(--line-2); border-radius: 20px; padding: 32px; box-shadow: var(--shadow); display: grid; gap: 18px; }
.contact-form label { display: grid; gap: 6px; font-size: 14px; font-weight: 500; color: var(--ink-2); }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form input[type="text"], .contact-form input[type="email"], .contact-form textarea {
  font: inherit; font-size: 15px; color: var(--ink);
  padding: 11px 13px; border-radius: 10px; border: 1px solid var(--line-2); background: var(--bg);
  transition: border-color .15s ease, background .15s ease, box-shadow .15s ease;
  width: 100%;
}
.contact-form textarea { resize: vertical; min-height: 110px; }
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--accent); background: #081019; box-shadow: 0 0 0 4px rgba(63, 240, 198, .15); }
.contact-form [aria-invalid="true"] { border-color: #FF6B6B !important; }
fieldset { border: 0; padding: 0; margin: 0; }
legend { font-size: 14px; font-weight: 500; color: var(--ink-2); margin-bottom: 8px; padding: 0; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { display: inline-flex !important; cursor: pointer; }
.chip input { position: absolute; opacity: 0; pointer-events: none; }
.chip span { padding: 8px 14px; border-radius: 999px; border: 1px solid var(--line-2); background: var(--bg); font-size: 14px; color: var(--ink-2); transition: all .15s ease; }
.chip:hover span { border-color: var(--muted); }
.chip input:checked + span { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); box-shadow: 0 0 16px -4px rgba(63, 240, 198, .6); }
.chip input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.form-note { font-size: 13px; color: var(--muted); text-align: center; }
.form-note a { color: var(--accent); }
.form-note.form-error { color: #FF9C8A; }
.hp-field { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.btn:disabled { opacity: .7; cursor: progress; transform: none; }

.form-success {
  background:
    radial-gradient(360px 220px at 50% 0%, rgba(63, 240, 198, .16), transparent 70%),
    var(--surface);
  border: 1px solid rgba(63, 240, 198, .4); border-radius: 20px;
  padding: 48px 32px; text-align: center; box-shadow: var(--glow);
}
.form-success:focus { outline: none; }
.form-success h3 { font-size: 1.35rem; margin: 20px 0 10px; }
.form-success p { color: var(--ink-2); max-width: 26em; margin-inline: auto; }
.form-success a { color: var(--accent); }
.success-icon { width: 56px; height: 56px; margin: 0 auto; border-radius: 50%; background: var(--grad); display: grid; place-items: center; box-shadow: 0 0 30px rgba(63, 240, 198, .5); }
.success-icon svg { width: 28px; height: 28px; fill: none; stroke: var(--on-accent); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- Footer ---------- */
.footer { padding: 48px 0 56px; border-top: 1px solid var(--line); background: var(--bg); }
.footer-inner { display: grid; grid-template-columns: auto 1fr auto; gap: 32px; align-items: center; }
.brand-footer .mark { width: 24px; height: 24px; }
.disclaimer { font-size: 13px; color: var(--muted); max-width: 60em; }
.copy { font-size: 13px; color: var(--muted); }

/* ---------- Reveal ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .flow { grid-template-columns: repeat(3, 1fr); }
  .flow-node:nth-child(3)::after { display: none; }
  .benefits { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 900px) {
  .hero { padding: 56px 0 80px; }
  .hero-grid, .privacy-grid, .dev-grid, .contact-grid, .problem-grid { grid-template-columns: 1fr; gap: 48px; }
  .receipt { margin: 0; }
  .vision-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-inner { grid-template-columns: 1fr; gap: 16px; }
  .section { padding: 80px 0; }

  .nav-toggle { display: block; }
  .nav-links {
    position: absolute; top: 68px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--bg); border-bottom: 1px solid var(--line);
    padding: 8px 20px 20px;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a:not(.btn) { padding: 14px 0; border-bottom: 1px solid var(--line); }
  .nav-links .btn { margin-top: 16px; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .wrap { width: calc(100% - 32px); }
  .flow { grid-template-columns: 1fr; }
  .flow-node:not(:last-child)::after { top: auto; bottom: -13px; right: 50%; transform: translateX(50%) rotate(135deg); display: block; }
  .benefits, .principles, .field-row { grid-template-columns: 1fr; }
  .withheld { grid-template-columns: 1fr 1fr; }
  .card, .contact-form, .pairwise { padding: 22px; }
  .code-card pre { font-size: 12.5px; padding: 20px; min-height: 0; }
}