/* harn landing. Black and white only: hierarchy by size, weight, opacity and inversion.
   Tokens are the only colours on the page; components never use raw values. */

@font-face {
  font-family: "Inter";
  src: url("/fonts/InterVariable-4.1.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("/fonts/JetBrainsMono-Regular-2.304.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("/fonts/JetBrainsMono-Bold-2.304.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: light;
  --canvas: #FFFFFF;
  --ink: #0A0A0A;
  --ink-2: rgba(10, 10, 10, .64);
  --ink-3: rgba(10, 10, 10, .44);   /* large text only (>= 18px): 3.1:1 on canvas */
  --hairline: rgba(10, 10, 10, .12);
  --grid: rgba(10, 10, 10, .035);
  --plate: #0A0A0A;
  --plate-ink: #F2F2F2;
  --plate-dim: rgba(242, 242, 242, .55);
  --plate-line: rgba(242, 242, 242, .14);
  --plate-edge: #0A0A0A;

  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --disp-w: 500;
  --gut: 40px;
  --frame: 1200px;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --canvas: #0A0A0A;
  --ink: #F2F2F2;
  --ink-2: rgba(242, 242, 242, .64);
  --ink-3: rgba(242, 242, 242, .44);
  --hairline: rgba(242, 242, 242, .14);
  --grid: rgba(242, 242, 242, .03);
  --plate: #000000;
  --plate-edge: rgba(242, 242, 242, .14);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --canvas: #0A0A0A;
    --ink: #F2F2F2;
    --ink-2: rgba(242, 242, 242, .64);
    --ink-3: rgba(242, 242, 242, .44);
    --hairline: rgba(242, 242, 242, .14);
    --grid: rgba(242, 242, 242, .03);
    --plate: #000000;
    --plate-edge: rgba(242, 242, 242, .14);
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  background-color: var(--canvas);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 72px 72px;
  color: var(--ink);
  font: 400 16px/1.6 var(--sans);
  font-optical-sizing: auto;
  overflow-wrap: break-word;
}
::selection { background: var(--ink); color: var(--canvas); }
img, svg { display: block; max-width: 100%; }
h1, h2, h3, p, figure, dl, dd, ol, ul { margin: 0; }
ol, ul { padding: 0; list-style: none; }
a { color: inherit; text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: .2em; }
a:hover { text-decoration-thickness: 2px; }
code, kbd { font-family: var(--mono); font-size: .875em; }
kbd {
  display: inline-block;
  min-width: 1.6em;
  padding: 0 .35em;
  border: 1px solid var(--hairline);
  text-align: center;
  line-height: 1.45;
}
:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
[hidden] { display: none; }

.sr-only {
  position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden;
  clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap; border: 0;
}
.skip {
  position: absolute; left: 8px; top: -100px; z-index: 100;
  padding: 12px 16px; background: var(--ink); color: var(--canvas);
  font: 700 12px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; text-decoration: none;
}
.skip:focus { top: 8px; }

/* The sheet: one framed column laid on the ruled ground. */
.sheet {
  max-width: var(--frame);
  margin: 0 auto;
  background: var(--canvas);
  border-left: 1px solid var(--hairline);
  border-right: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
}
main > section { border-top: 1px solid var(--hairline); padding: 72px var(--gut); }

.label {
  font: 400 12px/1.5 var(--mono);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink-2);
}

/* Nav */
.nav {
  display: flex; align-items: center; gap: 8px 28px; flex-wrap: wrap;
  min-height: 64px; padding: 0 var(--gut);
}
.brand {
  font: 700 20px/1 var(--mono); letter-spacing: -.02em; text-decoration: none;
  display: inline-flex; align-items: center; min-height: 44px;
}
.nav-links { display: flex; gap: 0 24px; margin-left: auto; flex-wrap: wrap; }
.nav-links a, .theme {
  display: inline-flex; align-items: center; min-height: 44px;
  font: 400 12px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase;
  color: var(--ink-2); text-decoration: none;
}
.nav-links a:hover { color: var(--ink); text-decoration: underline; text-decoration-thickness: 1px; }
.theme {
  gap: 8px; padding: 0 0 0 4px; background: none; border: 0; cursor: pointer;
  -webkit-appearance: none; appearance: none; touch-action: manipulation;
}
.theme::before {
  content: ""; width: 11px; height: 11px; border: 1px solid currentColor;
}
.theme[aria-pressed="true"]::before { background: currentColor; }
.theme:hover { color: var(--ink); }
html:not(.js) .theme { display: none; }

/* Hero */
.hero { padding-top: 88px; padding-bottom: 80px; }
h1 {
  margin-top: 20px;
  max-width: 17ch;
  font-weight: var(--disp-w);
  font-size: clamp(40px, 7vw, 92px);
  line-height: .98;
  letter-spacing: -.045em;
  text-wrap: balance;
}
.lede {
  margin-top: 28px;
  max-width: 60ch;
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink-2);
}
.lede code { color: var(--ink); }

.cmd {
  display: flex; align-items: stretch; flex-wrap: wrap;
  margin-top: 36px; width: fit-content; max-width: 100%;
  border: 1px solid var(--ink);
}
.cmd code {
  display: flex; align-items: center; gap: .6ch;
  padding: 12px 18px; font-size: 14.5px; line-height: 1.4; color: var(--ink);
  overflow-wrap: anywhere;
}
.prompt { color: var(--ink-2); user-select: none; -webkit-user-select: none; }
.copy {
  display: none;
  align-items: center; justify-content: center;
  min-width: 88px; min-height: 46px; padding: 0 18px;
  border: 0; border-left: 1px solid var(--ink);
  background: var(--ink); color: var(--canvas);
  font: 700 12px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase;
  cursor: pointer; touch-action: manipulation;
}
.copy:hover { text-decoration: underline; text-underline-offset: .25em; }
.copy:active { background: var(--ink-2); }
.copy:focus-visible { outline-offset: 3px; }
.js .copy { display: inline-flex; }

.after {
  margin-top: 16px;
  font: 400 13px/1.6 var(--mono);
  color: var(--ink-2);
}
.after code { font-size: 1em; color: var(--ink); }
.after a { color: var(--ink); }
.sep { padding: 0 .5ch; }
.nw { white-space: nowrap; }
.trust {
  display: flex; flex-wrap: wrap; gap: 6px 0;
  margin-top: 40px; padding-top: 16px; border-top: 1px solid var(--hairline);
  font: 400 12px/1.5 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-2);
}
.trust li + li::before { content: "·"; padding: 0 1.2ch; }

/* Numbers strip: four ruled cells. */
.stats { padding-top: 40px; padding-bottom: 48px; }
.stat-grid {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 20px;
  border-top: 1px solid var(--hairline); border-left: 1px solid var(--hairline);
}
.stat {
  display: flex; flex-direction: column-reverse; justify-content: flex-end; gap: 10px;
  padding: 24px 24px 26px;
  border-right: 1px solid var(--hairline); border-bottom: 1px solid var(--hairline);
}
.stat dd {
  font-weight: var(--disp-w);
  font-size: clamp(34px, 4.2vw, 56px);
  line-height: 1;
  letter-spacing: -.04em;
  font-variant-numeric: tabular-nums;
}
.stat dt {
  font: 400 12px/1.5 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-2);
}

/* Terminal plate: real text, 80 columns, scaled by its container. */
.fig { padding-top: 48px; }
.fig-head { display: flex; justify-content: space-between; gap: 8px 24px; flex-wrap: wrap; margin-bottom: 16px; }
.plate {
  background: var(--plate);
  color: var(--plate-ink);
  border: 1px solid var(--plate-edge);
}
.plate ::selection { background: var(--plate-ink); color: var(--plate); }
.plate :focus-visible { outline-color: var(--plate-ink); }
.tabs {
  display: none;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 1px;
  background: var(--plate-line);
  border-bottom: 1px solid var(--plate-line);
}
.js .tabs { display: grid; }
.tabs [role="tab"] {
  min-height: 46px; padding: 6px 8px;
  background: var(--plate); color: var(--plate-dim);
  border: 0; cursor: pointer; touch-action: manipulation;
  font: 400 12px/1.25 var(--mono); letter-spacing: .06em; text-transform: uppercase;
}
.tabs [role="tab"]:hover { color: var(--plate-ink); text-decoration: underline; text-underline-offset: .3em; }
.tabs [role="tab"][aria-selected="true"] {
  background: var(--plate-ink); color: var(--plate); font-weight: 700; text-decoration: none;
}
.tabs [role="tab"]:focus-visible { outline: 2px solid var(--plate-ink); outline-offset: -5px; }
.tabs [role="tab"][aria-selected="true"]:focus-visible { outline-color: var(--plate); }

.panel { container-type: inline-size; padding: 20px 24px 28px; }
.panel + .panel { border-top: 1px solid var(--plate-line); }
.js .panel { display: none; }
.js .panel.is-on { display: block; }
.js .panel + .panel { border-top: 0; }
/* One column, 80 terminal cells wide: 80 x 0.6em = 48em; 48.3 absorbs rounding. */
.term {
  width: 80ch;
  max-width: 100%;
  margin: 0 auto;
  font-family: var(--mono);
  font-size: clamp(7px, calc(100cqi / 48.3), 18px);
  /* Where round() exists: a whole-pixel cell (advance = 0.6em), so block bars meet without seams. */
  font-size: clamp(7px, calc(round(down, 100cqi / 80, 1px) / .6), 18.3334px);
}
.pname {
  margin-bottom: 6px;
  font: 700 12px/1.5 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--plate-ink);
}
.js .pname { display: none; }
.pnote {
  margin: 0 0 14px;
  font: 400 12px/1.55 var(--mono); color: var(--plate-dim);
}
.scr + .pnote { margin-top: 24px; }
.scr {
  overflow-x: auto;
  overscroll-behavior-x: contain;
}
.scr:focus-visible { outline-offset: 4px; }
.scr pre {
  width: 80ch;
  margin: 0;
  font-family: var(--mono);
  font-size: 1em;
  line-height: 1.3;
  white-space: pre;
  color: var(--plate-ink);
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
}
.fig-cap { margin-top: 14px; font: 400 12px/1.5 var(--mono); color: var(--ink-2); }

/* Section heads */
.sec-head { margin-bottom: 40px; }
h2 {
  margin-top: 12px;
  max-width: 18ch;
  font-weight: var(--disp-w);
  font-size: clamp(30px, 4.4vw, 56px);
  line-height: 1.02;
  letter-spacing: -.04em;
  text-wrap: balance;
}
h2.label { margin-top: 0; max-width: none; font-weight: 400; font-size: 12px; line-height: 1.5; letter-spacing: .08em; }

/* How it works: numbered rows, not cards. */
.how { padding-bottom: 32px; }
.rows { border-top: 1px solid var(--hairline); }
.row {
  display: grid;
  grid-template-columns: 112px minmax(0, 50ch) minmax(0, 1fr);
  gap: 24px 28px;
  padding: 36px 0 40px;
  border-bottom: 1px solid var(--hairline);
}
.row:last-child { border-bottom: 0; }
.num {
  font-weight: var(--disp-w);
  font-size: 48px;
  line-height: .9;
  letter-spacing: -.04em;
  color: var(--ink-3);
  font-variant-numeric: tabular-nums;
}
.row h3 {
  font-weight: 600;
  font-size: 23px;
  line-height: 1.2;
  letter-spacing: -.025em;
}
.row p { margin-top: 12px; color: var(--ink-2); }
.row p code, .row p kbd, .qa code, .qa kbd, .pr-list code { color: var(--ink); }
.ev {
  align-self: start;
  justify-self: end;
  width: 100%;
  max-width: 520px;
  background: var(--plate);
  color: var(--plate-ink);
  border: 1px solid var(--plate-edge);
}
.ev figcaption {
  padding: 10px 14px 9px;
  border-bottom: 1px solid var(--plate-line);
  font: 400 11px/1.4 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--plate-dim);
}
.ev pre {
  margin: 0;
  padding: 14px 14px 16px;
  font: 400 11.5px/1.6 var(--mono);
  white-space: pre-wrap;
  font-variant-ligatures: none;
}
.ev ::selection { background: var(--plate-ink); color: var(--plate); }

/* Principles: a ruled cell group. */
.principles { padding-top: 40px; padding-bottom: 56px; }
.pr-list {
  display: grid; grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 1px; margin-top: 20px;
  background: var(--hairline); border: 1px solid var(--hairline);
}
.pr-list li { display: flex; flex-direction: column; gap: 10px; padding: 22px 20px 26px; background: var(--canvas); }
.pr-list strong {
  font: 700 12px/1.5 var(--mono); letter-spacing: .06em; text-transform: uppercase;
}
.pr-list strong code { font-size: 1em; text-transform: none; letter-spacing: 0; }
.pr-list span { font-size: 15px; line-height: 1.55; color: var(--ink-2); }

/* FAQ: static, two ruled columns. */
.faq-grid {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px; background: var(--hairline); border: 1px solid var(--hairline);
}
.qa { padding: 26px 28px 30px; background: var(--canvas); }
.qa h3 { font-size: 18px; font-weight: 600; line-height: 1.35; letter-spacing: -.01em; }
.qa p { margin-top: 10px; max-width: 60ch; color: var(--ink-2); }

/* Final CTA */
.end { padding-top: 96px; padding-bottom: 104px; }
.end h2 { margin-top: 0; max-width: 14ch; font-size: clamp(38px, 6vw, 80px); line-height: .98; letter-spacing: -.045em; }
.end-lede { margin-top: 24px; max-width: 56ch; font-size: 17px; color: var(--ink-2); }
.end-links { display: flex; flex-wrap: wrap; gap: 0 28px; margin-top: 28px; }
.end-links a {
  display: inline-flex; align-items: center; min-height: 44px;
  font: 400 13px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase;
}

/* Footer */
.foot {
  display: flex; flex-wrap: wrap; align-items: center; gap: 4px 24px;
  padding: 20px var(--gut) 24px; border-top: 1px solid var(--hairline);
  font: 400 12px/1.5 var(--mono); color: var(--ink-2);
}
.foot a { display: inline-flex; align-items: center; min-height: 44px; }
.brand-sm { font-weight: 700; color: var(--ink); }

/* 404 */
.lost { padding: 112px var(--gut) 120px; }
.lost h1 { max-width: 14ch; }
.lost p { margin-top: 24px; max-width: 52ch; font-size: 17px; color: var(--ink-2); }
.lost .home { margin-top: 36px; display: inline-flex; align-items: center; min-height: 44px; font: 700 13px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; }

@media (max-width: 1100px) {
  .pr-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .pr-list li:last-child:nth-child(odd) { grid-column: 1 / -1; }
  .row { grid-template-columns: 96px minmax(0, 1fr); }
  .row .ev { max-width: 600px; }
  .row .ev { grid-column: 2; justify-self: start; }
}
@media (max-width: 900px) {
  :root { --gut: 24px; }
  main > section { padding-top: 56px; padding-bottom: 56px; }
  .hero { padding-top: 64px; }
  .stat-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .tabs { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .tabs::after { content: ""; background: var(--plate); }
  .panel { padding: 16px 12px 20px; }
  .faq-grid { grid-template-columns: minmax(0, 1fr); }
  .row { grid-template-columns: 54px minmax(0, 1fr); gap: 16px 16px; }
  .num { font-size: 32px; }
  .row .ev { grid-column: 1 / -1; max-width: none; }
}
@media (max-width: 600px) {
  :root { --gut: 16px; }
  .nav { gap: 0 16px; }
  .nav-links { gap: 0 16px; margin-left: 0; order: 3; width: 100%; }
  .theme { margin-left: auto; }
  .stat { padding: 18px 16px 20px; }
  .pr-list { grid-template-columns: minmax(0, 1fr); }
  .pr-list li:last-child:nth-child(odd) { grid-column: auto; }
  .panel { padding: 12px 8px 16px; }
  .qa { padding: 22px 18px 24px; }
  .cmd { width: 100%; flex-direction: column; }
  .cmd code { padding: 12px 14px; font-size: 13px; }
  .copy { width: 100%; border-left: 0; border-top: 1px solid var(--ink); }
  .trust { flex-direction: column; gap: 4px; }
  .trust li + li::before { content: none; }
}

@media (max-width: 380px) {
  .cmd code { padding: 12px; font-size: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}