/* zerobehind.com. Same tokens and typeface as the product (Recursive, self-hosted).
   No external requests, no inline styles: the site runs under a strict CSP. */

@font-face {
  font-family: "Recursive";
  font-style: oblique 0deg 15deg;
  font-weight: 300 1000;
  font-display: swap;
  src: url(/fonts/recursive-latin.woff2) format("woff2-variations");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Recursive";
  font-style: oblique 0deg 15deg;
  font-weight: 300 1000;
  font-display: swap;
  src: url(/fonts/recursive-latin-ext.woff2) format("woff2-variations");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+1E00-1E9F, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

:root {
  color-scheme: light dark;
  --plane: #edf0f3;
  --surface: #f8fafb;
  --raised: #ffffff;
  --ink: #15202b;
  --ink-2: #4c5a68;
  --muted: #5f6c79;
  --hair: #d6dde3;
  --s1: #2a78d6;
  --s1-ink: #1c5cab;
  --s2: #eb6834;
  --good: #0ca30c;
  --good-ink: #006300;
  --crit-ink: #a82a2a;
  --btn: #15202b;
  --btn-ink: #ffffff;
  --focus: #2a78d6;
  --sans: "Recursive", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --r: 10px;
  --shadow: 0 1px 2px rgba(21, 32, 43, .06), 0 12px 32px rgba(21, 32, 43, .08);
}
@media (prefers-color-scheme: dark) {
  :root {
    --plane: #0f151b;
    --surface: #161e26;
    --raised: #1b2530;
    --ink: #e7ecf0;
    --ink-2: #a9b4be;
    --muted: #93a0ac;
    --hair: #26313b;
    --s1: #3987e5;
    --s1-ink: #7db4f2;
    --s2: #e9713f;
    --good: #2fbf2f;
    --good-ink: #4fd04f;
    --crit-ink: #f08a8a;
    --btn: #e7ecf0;
    --btn-ink: #0f151b;
    --focus: #6aa8f0;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 12px 32px rgba(0, 0, 0, .35);
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  margin: 0;
  background: var(--plane);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.55;
  font-variation-settings: "MONO" 0, "CASL" 0;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, p, ul, ol, dl, dd, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: var(--s1-ink); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 4px; }

.wrap { width: min(1120px, 100% - 40px); margin-inline: auto; }
.narrow { width: min(760px, 100% - 40px); }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.skip { position: absolute; left: 12px; top: -60px; background: var(--btn); color: var(--btn-ink); padding: 10px 14px; border-radius: 8px; z-index: 20; }
.skip:focus { top: 12px; }

/* ---------- header ---------- */
.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--plane) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--hair); }
.top-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 60px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 800; font-size: 18px; letter-spacing: -.01em; }
.mark { width: 34px; height: 17px; fill: var(--s1); }
.mark .ring { fill: none; stroke: var(--s1); stroke-width: 2.4; }
.nav { display: flex; align-items: center; gap: 22px; font-size: 15px; }
.nav a:not(.btn) { color: var(--ink-2); text-decoration: none; font-weight: 550; }
.nav a:not(.btn):hover { color: var(--ink); }

.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 0 22px; border: 1px solid var(--btn); border-radius: 999px; background: var(--btn); color: var(--btn-ink); font: inherit; font-weight: 700; text-decoration: none; cursor: pointer; transition: transform .12s ease, box-shadow .12s ease; }
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); }
.btn.small { min-height: 38px; padding: 0 16px; font-size: 14px; }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--hair); }
.btn[disabled] { opacity: .6; cursor: progress; transform: none; box-shadow: none; }

/* ---------- hero ---------- */
.hero { padding: 72px 0 64px; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr); gap: 56px; align-items: center; }
.eyebrow { font-size: 13px; font-weight: 700; letter-spacing: .09em; text-transform: uppercase; color: var(--s1-ink); margin-bottom: 14px; }
h1 { font-size: clamp(38px, 5.4vw, 62px); line-height: 1.04; letter-spacing: -.03em; font-weight: 850; text-wrap: balance; }
h1 .zero { color: var(--s1); font-variation-settings: "MONO" 1, "CASL" 0; font-style: oblique 8deg; }
.lead { margin-top: 22px; font-size: 20px; line-height: 1.5; color: var(--ink-2); max-width: 54ch; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.fine { margin-top: 18px; font-size: 14.5px; color: var(--muted); max-width: 56ch; }

.pair { background: var(--raised); border: 1px solid var(--hair); border-radius: 18px; padding: 26px; box-shadow: var(--shadow); }
.pair-row { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 0; }
.node { border: 1px solid var(--hair); background: var(--surface); border-radius: 10px; padding: 12px 14px; min-width: 132px; }
.node-name { display: block; font-weight: 750; font-variation-settings: "MONO" 1; font-size: 15px; }
.node-role { display: flex; align-items: center; gap: 7px; font-size: 13px; color: var(--muted); margin-top: 2px; }
.dot { width: 9px; height: 9px; border-radius: 50%; display: inline-block; }
.dot.s1 { background: var(--s1); }
.dot.s2 { background: var(--s2); }
.wire { position: relative; height: 2px; min-width: 44px; background: var(--good); margin: 0 2px; }
.wire::after { content: ""; position: absolute; right: -1px; top: -5px; border: 6px solid transparent; border-left-color: var(--good); border-right-width: 0; }
.wire i { position: absolute; top: -3px; left: 0; width: 8px; height: 8px; border-radius: 50%; background: var(--s1); opacity: 0; animation: flow 2.4s linear infinite; }
.wire i:nth-child(2) { animation-delay: .8s; }
.wire i:nth-child(3) { animation-delay: 1.6s; }
@keyframes flow { 0% { left: 0; opacity: 0; } 10% { opacity: 1; } 85% { opacity: 1; } 100% { left: calc(100% - 14px); opacity: 0; } }
.readout { display: flex; align-items: baseline; gap: 14px; margin: 26px 0 18px; }
.readout .big { font-size: 92px; line-height: .86; font-weight: 900; color: var(--good-ink); letter-spacing: -.04em; }
.readout .unit { font-size: 19px; font-weight: 650; color: var(--ink-2); }
.pair-facts { display: grid; gap: 0; border-top: 1px solid var(--hair); }
.pair-facts > div { display: flex; justify-content: space-between; gap: 16px; padding: 10px 0; border-bottom: 1px solid var(--hair); font-size: 15px; }
.pair-facts dt { color: var(--muted); }
.pair-facts dd { font-weight: 650; text-align: right; }
.pair-facts .ok { color: var(--good-ink); }
.pair figcaption { margin-top: 12px; font-size: 12.5px; color: var(--muted); }

/* ---------- proof ---------- */
.proof { background: var(--ink); color: var(--plane); padding: 44px 0 36px; }
@media (prefers-color-scheme: dark) { .proof { background: var(--surface); color: var(--ink); border-block: 1px solid var(--hair); } }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 28px; }
.stats .num { display: block; font-size: clamp(34px, 4vw, 48px); line-height: 1; font-weight: 850; letter-spacing: -.03em; }
.stats .lbl { display: block; margin-top: 10px; font-size: 15px; line-height: 1.4; opacity: .82; max-width: 26ch; }
.source { margin-top: 28px; padding-top: 18px; border-top: 1px solid color-mix(in srgb, currentColor 22%, transparent); font-size: 14px; opacity: .78; max-width: 92ch; }

/* ---------- sections ---------- */
.section { padding: 88px 0; }
.section.alt { background: var(--surface); border-block: 1px solid var(--hair); }
h2 { font-size: clamp(28px, 3.4vw, 40px); line-height: 1.12; letter-spacing: -.025em; font-weight: 820; text-wrap: balance; max-width: 22ch; }
h3 { font-size: 19px; line-height: 1.3; font-weight: 750; letter-spacing: -.01em; }
.section p { color: var(--ink-2); }

.cards { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin-top: 40px; }
.card { background: var(--raised); border: 1px solid var(--hair); border-radius: var(--r); padding: 24px; }
.card h3 { margin-bottom: 8px; }
.card p { font-size: 16px; }

.steps { counter-reset: step; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 28px; margin-top: 40px; }
.steps li { counter-increment: step; border-top: 3px solid var(--s1); padding-top: 18px; }
.steps li::before { content: counter(step, decimal-leading-zero); display: block; font-variation-settings: "MONO" 1; font-weight: 800; font-size: 15px; color: var(--s1-ink); margin-bottom: 8px; }
.steps h3 { margin-bottom: 8px; }
.steps p { font-size: 16px; }
.note { margin-top: 36px; padding: 16px 20px; border-left: 4px solid var(--s2); background: var(--raised); border-radius: 0 var(--r) var(--r) 0; max-width: 78ch; }

.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 56px; align-items: start; }
.split h2 { margin-bottom: 18px; }
.split p + p { margin-top: 14px; }
.checks { display: grid; gap: 12px; }
.checks li { position: relative; padding: 16px 18px 16px 50px; background: var(--raised); border: 1px solid var(--hair); border-radius: var(--r); color: var(--ink-2); font-size: 16px; }
.checks li::before { content: ""; position: absolute; left: 18px; top: 21px; width: 16px; height: 9px; border-left: 3px solid var(--good); border-bottom: 3px solid var(--good); transform: rotate(-45deg); }
.checks strong { color: var(--ink); font-weight: 720; }

details { border-bottom: 1px solid var(--hair); }
details:first-of-type { margin-top: 28px; border-top: 1px solid var(--hair); }
summary { cursor: pointer; padding: 18px 34px 18px 0; font-weight: 700; font-size: 18px; list-style: none; position: relative; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 4px; top: 14px; font-size: 24px; font-weight: 500; color: var(--muted); }
details[open] summary::after { content: "\2212"; }
details p { padding: 0 0 20px; max-width: 68ch; }

/* ---------- form ---------- */
.access { background: var(--plane); }
.form { background: var(--raised); border: 1px solid var(--hair); border-radius: 16px; padding: 28px; box-shadow: var(--shadow); display: grid; gap: 16px; }
.field label { display: block; font-size: 14.5px; font-weight: 650; margin-bottom: 6px; color: var(--ink); }
.field .opt { font-weight: 450; color: var(--muted); margin-left: 4px; }
.field input, .field select, .field textarea { width: 100%; min-height: 46px; padding: 10px 12px; font: inherit; font-size: 16px; color: var(--ink); background: var(--surface); border: 1px solid var(--hair); border-radius: 8px; }
.field textarea { resize: vertical; min-height: 104px; }
.field input:focus-visible, .field select:focus-visible, .field textarea:focus-visible { outline: 3px solid var(--focus); outline-offset: 1px; border-color: var(--focus); }
.field.two { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.field.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.field .bad { border-color: var(--crit-ink); }
.form .btn { justify-self: start; }
.form-status { min-height: 1.5em; font-size: 15.5px; font-weight: 600; }
.form-status.ok { color: var(--good-ink); }
.form-status.err { color: var(--crit-ink); }

/* ---------- footer ---------- */
.foot { border-top: 1px solid var(--hair); background: var(--surface); padding: 40px 0 28px; font-size: 15px; color: var(--ink-2); }
.foot-row { display: flex; justify-content: space-between; gap: 32px; flex-wrap: wrap; }
.foot-row p { margin-top: 10px; }
.foot-links { display: flex; gap: 24px; flex-wrap: wrap; align-items: center; }
.legal { margin-top: 28px; padding-top: 18px; border-top: 1px solid var(--hair); font-size: 13.5px; color: var(--muted); }

/* ---------- plain pages ---------- */
.page { padding: 64px 0 88px; }
.page h1 { font-size: clamp(32px, 4vw, 44px); margin-bottom: 18px; }
.page h2 { font-size: 22px; margin: 34px 0 10px; max-width: none; }
.page p, .page li { color: var(--ink-2); max-width: 72ch; }
.page p + p { margin-top: 12px; }
.page ul { list-style: disc; padding-left: 22px; display: grid; gap: 6px; }
.page .btn { margin-top: 28px; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .hero { padding: 48px 0; }
  .hero-grid, .split { grid-template-columns: minmax(0, 1fr); gap: 40px; }
  .cards, .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .section { padding: 64px 0; }
}
@media (max-width: 620px) {
  body { font-size: 16px; }
  .nav a:not(.btn) { display: none; }
  .cards, .steps { grid-template-columns: minmax(0, 1fr); }
  .lead { font-size: 18px; }
  .pair { padding: 18px; }
  .node { min-width: 0; padding: 10px; }
  .node-name { font-size: 14px; }
  .node-role { font-size: 12px; }
  .readout .big { font-size: 64px; }
  .field.two { grid-template-columns: 1fr; }
  .cta-row .btn { flex: 1 1 100%; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .wire i { animation: none; opacity: 1; left: 45%; }
  .wire i:nth-child(2), .wire i:nth-child(3) { display: none; }
  .btn { transition: none; }
}