/* ==========================================================================
   Brick 42 — site stylesheet
   Edition 2.0 identity. Achromatic by decision: white ground or full black
   plate, near-black ink, no accent. Tokens are the identity contract —
   do not substitute values.
   ========================================================================== */

:root {
  --bg:           oklch(1 0 0);           /* #ffffff  ground              */
  --surface:      oklch(0.975 0 0);       /* #f6f6f6  raised areas        */
  --fg:           oklch(0.205 0.005 264); /* #161719  ink, 17.91:1        */
  --muted:        oklch(0.48 0.005 264);  /* #5c5e60  secondary, 6.54:1   */
  --border:       oklch(0.905 0.004 264); /* #dee0e2  hairlines           */
  --brand-black:  #000000;                /* wordmark + black plates      */
  --on-black:     oklch(0.75 0.005 264);  /* muted text on black plate    */
  /* --accent is reserved by the identity and spent nowhere. */

  --font-display: 'Avenir Next', 'Avenir', 'Century Gothic', 'Futura', system-ui, sans-serif;
  --font-body:    -apple-system, BlinkMacSystemFont, 'Helvetica Neue', 'Segoe UI', system-ui, sans-serif;
  --font-mono:    ui-monospace, 'SF Mono', 'JetBrains Mono', Menlo, monospace;

  --fs-h1:   clamp(40px, 5.4vw, 72px);
  --fs-h2:   clamp(30px, 3.6vw, 46px);
  --fs-h3:   21px;
  --fs-lead: 19px;
  --fs-body: 16px;
  --fs-meta: 13px;

  --gap-xs: 8px; --gap-sm: 12px; --gap-md: 20px; --gap-lg: 32px;
  --gap-xl: 56px; --gap-2xl: 96px;
  --container: 1120px;
  --gutter: 32px;
  --radius: 10px;
  --radius-lg: 16px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.55;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; }
a:focus-visible, button:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--fg); outline-offset: 3px; border-radius: 2px;
}
button { font: inherit; cursor: pointer; }
p { text-wrap: pretty; }
h1, h2, h3, h4 { text-wrap: balance; margin: 0; }

.container { max-width: var(--container); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-block: clamp(52px, 8vw, var(--gap-2xl)); }
.section + .section { border-top: 1px solid var(--border); }
.section-head { max-width: 720px; margin-bottom: var(--gap-xl); }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--gap-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap-lg); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--gap-md); }
@media (max-width: 920px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 520px) { .grid-4 { grid-template-columns: 1fr; } }

/* type ------------------------------------------------------------------- */
h1, .h1 { font-family: var(--font-display); font-size: var(--fs-h1); line-height: 1.03; letter-spacing: -0.026em; }
h2, .h2 { font-family: var(--font-display); font-size: var(--fs-h2); line-height: 1.1; letter-spacing: -0.02em; }
h3, .h3 { font-family: var(--font-display); font-size: var(--fs-h3); font-weight: 600; line-height: 1.3; letter-spacing: -0.005em; }
.lead { font-size: var(--fs-lead); line-height: 1.55; color: var(--muted); max-width: 62ch; margin: 0; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

/* the square period, reused as the section tick — the identity's one device */
.eyebrow {
  display: flex; align-items: center; gap: 9px;
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.09em;
  text-transform: uppercase; color: var(--muted); margin: 0 0 var(--gap-md);
}
.eyebrow::before { content: ''; width: 7px; height: 7px; background: var(--fg); flex: none; }
.meta { font-family: var(--font-mono); font-size: var(--fs-meta); color: var(--muted); }
.num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* skip link -------------------------------------------------------------- */
.skip-link {
  position: absolute; left: var(--gap-sm); top: -56px; z-index: 40;
  background: var(--fg); color: var(--bg); padding: 10px 16px;
  border-radius: var(--radius); font-size: 14px; font-weight: 500;
  text-decoration: none; transition: top .15s ease;
}
.skip-link:focus-visible { top: var(--gap-sm); }

/* nav -------------------------------------------------------------------- */
.topnav {
  position: sticky; top: 0; z-index: 30;
  background: color-mix(in oklch, var(--bg) 92%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.topnav-inner { display: flex; align-items: center; gap: var(--gap-lg); padding-block: 14px; }
.topnav .brand { display: inline-flex; align-items: center; }
.topnav .brand img { height: 20px; width: auto; }
.primary-nav {
  display: flex; align-items: center; gap: var(--gap-lg);
  margin-left: auto;
}
.primary-nav a {
  font-size: 14px; color: var(--muted); text-decoration: none; padding-block: 5px;
}
.primary-nav a:hover { color: var(--fg); text-decoration: underline; text-underline-offset: 4px; }
.nav-actions { display: flex; align-items: center; gap: var(--gap-sm); }
.nav-toggle {
  display: none; align-items: center; gap: 8px;
  background: transparent; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 8px 14px; font-size: 14px; color: var(--fg);
}
.nav-toggle:hover { border-color: var(--fg); }
.nav-toggle .bars { position: relative; width: 14px; height: 10px; }
.nav-toggle .bars::before, .nav-toggle .bars::after {
  content: ''; position: absolute; left: 0; width: 14px; height: 1.5px; background: var(--fg);
}
.nav-toggle .bars::before { top: 0; } .nav-toggle .bars::after { bottom: 0; }

@media (max-width: 980px) {
  .topnav-inner { flex-wrap: wrap; }
  .nav-toggle { display: inline-flex; margin-left: auto; }
  .primary-nav {
    order: 3; width: 100%; margin-left: 0; flex-direction: column;
    align-items: stretch; gap: 0; border-top: 1px solid var(--border);
    margin-top: 14px; display: none;
  }
  .primary-nav.is-open { display: flex; }
  .primary-nav a { padding: 13px 2px; border-bottom: 1px solid var(--border); font-size: 15px; }
  .nav-actions { order: 4; width: 100%; padding-top: 16px; }
  .nav-actions .btn { width: 100%; justify-content: center; }
}

/* buttons ---------------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 20px; border-radius: var(--radius); border: 1px solid transparent;
  font-size: 15px; font-weight: 500; letter-spacing: -0.005em; text-decoration: none;
  transition: background .15s ease, border-color .15s ease, color .15s ease, transform .05s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--fg); color: var(--bg); border-color: var(--fg); }
.btn-primary:hover { background: var(--brand-black); border-color: var(--brand-black); color: var(--bg); }
.btn-secondary { background: transparent; color: var(--fg); border-color: var(--border); }
.btn-secondary:hover { border-color: var(--fg); background: var(--surface); }
.btn-ghost { background: transparent; color: var(--fg); border-color: transparent; padding-inline: 8px; }
.btn-ghost:hover { text-decoration: underline; text-underline-offset: 4px; }
.btn-arrow::after { content: '→'; transition: transform .15s ease; }
.btn-arrow:hover::after { transform: translateX(2px); }
.on-black .btn-secondary { color: var(--bg); border-color: color-mix(in oklch, var(--bg) 34%, var(--brand-black)); }
.on-black .btn-secondary:hover { border-color: var(--bg); background: transparent; }
.on-black .btn-ghost { color: var(--bg); }
.on-black .btn-primary { background: var(--bg); color: var(--brand-black); border-color: var(--bg); }
.on-black .btn-primary:hover { background: color-mix(in oklch, var(--bg) 88%, var(--brand-black)); border-color: color-mix(in oklch, var(--bg) 88%, var(--brand-black)); color: var(--brand-black); }

/* hero ------------------------------------------------------------------- */
.hero { padding-block: clamp(56px, 9vw, 120px); }
.hero-grid {
  display: grid; grid-template-columns: 1.25fr 0.75fr; gap: var(--gap-xl); align-items: end;
}
@media (max-width: 980px) { .hero-grid { grid-template-columns: 1fr; gap: var(--gap-lg); } }
.hero h1 { margin-bottom: var(--gap-md); max-width: 16ch; }
.hero .lead { margin-bottom: var(--gap-lg); }
.hero-cta { display: flex; gap: var(--gap-sm); flex-wrap: wrap; align-items: center; }

.trust-band { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: var(--surface); }
.trust-inner { display: flex; flex-wrap: wrap; align-items: center; gap: var(--gap-md) var(--gap-xl); padding-block: 18px; }
.trust-item { display: inline-flex; align-items: center; gap: 9px; font-family: var(--font-mono); font-size: 12.5px; color: var(--muted); }
.trust-item::before { content: ''; width: 8px; height: 8px; background: var(--fg); flex: none; }

/* answers / spreadsheet -------------------------------------------------- */
.q-table { width: 100%; border-collapse: collapse; }
.q-table td { padding: 16px 0; border-bottom: 1px solid var(--border); vertical-align: baseline; }
.q-table .q { font-size: 17px; padding-right: var(--gap-lg); }
.q-table .a { font-family: var(--font-mono); font-size: 12.5px; color: var(--muted); text-align: right; }
@media (max-width: 640px) {
  .q-table tr, .q-table td { display: block; }
  .q-table td { padding: 0; border-bottom: 0; }
  .q-table tr { padding: 14px 0; border-bottom: 1px solid var(--border); }
  .q-table .a { text-align: left; margin-top: 4px; }
}

/* capability cards ------------------------------------------------------- */
.cap-card {
  display: flex; flex-direction: column; gap: var(--gap-sm);
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 26px; background: var(--bg); text-decoration: none;
  transition: border-color .15s ease, background .15s ease;
}
.cap-card:hover { border-color: var(--fg); background: var(--surface); }
.cap-card h3 { margin: 0; }
.cap-flag { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.cap-card p { font-size: 15px; color: var(--muted); margin: 0; }
.cap-card .cap-list { list-style: none; margin: auto 0 0; padding: 0; }
.cap-card .cap-list li { font-size: 14px; color: var(--fg); padding: 7px 0; border-top: 1px solid var(--border); }
.cap-card .cap-list li:first-child { margin-top: var(--gap-md); }
.cap-more { font-size: 14px; font-weight: 500; margin-top: var(--gap-md); }
.cap-card:hover .cap-more { text-decoration: underline; text-underline-offset: 4px; }

/* answer panel ----------------------------------------------------------- */
.panel {
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  background: var(--bg); overflow: hidden;
}
.panel-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 20px; border-bottom: 1px solid var(--border);
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted);
}
.panel-head img { height: 11px; width: auto; }
.panel table { width: 100%; border-collapse: collapse; font-size: 14px; }
.panel th, .panel td { padding: 13px 20px; text-align: left; border-bottom: 1px solid var(--border); }
.panel th { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); font-weight: 500; }
.panel td.num-col { font-family: var(--font-mono); font-variant-numeric: tabular-nums; color: var(--muted); }
.panel tbody tr:last-child td { border-bottom: 0; }
.panel-note { padding: 13px 20px; border-top: 1px solid var(--border); font-family: var(--font-mono); font-size: 11.5px; color: var(--muted); line-height: 1.5; }
.panel-scroll { overflow-x: auto; }
.panel table.status-table { min-width: 520px; }
@media (max-width: 560px) { .panel-head { flex-wrap: wrap; gap: 4px; } }

/* proof ------------------------------------------------------------------ */
.proof-card { border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 28px; background: var(--bg); }
.proof-card h3 { margin-bottom: var(--gap-sm); }
.proof-card p { font-size: 15px; color: var(--muted); }
.proof-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: var(--gap-md); }
.tag {
  font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.04em;
  border: 1px solid var(--border); border-radius: 100px; padding: 4px 11px; color: var(--muted);
}

/* black band ------------------------------------------------------------- */
.on-black { background: var(--brand-black); color: var(--bg); }
.on-black h2 { color: var(--bg); }
.on-black .lead { color: var(--on-black); }
.on-black .eyebrow { color: var(--on-black); }
.on-black .eyebrow::before { background: var(--bg); }
.on-black .meta { color: var(--on-black); }
.tool-band { border-top: 0; }
.tool-grid { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: var(--gap-xl); align-items: center; }
@media (max-width: 980px) { .tool-grid { grid-template-columns: 1fr; gap: var(--gap-lg); } }
.tool-facts { list-style: none; margin: 0; padding: 0; }
.tool-facts li { border-top: 1px solid color-mix(in oklch, var(--bg) 24%, var(--brand-black)); padding: 16px 0; display: flex; gap: var(--gap-md); }
.tool-facts .k { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--on-black); min-width: 130px; }
.tool-facts .v { font-size: 15px; color: var(--bg); }

/* insights --------------------------------------------------------------- */
.article-row {
  display: grid; grid-template-columns: 150px 1fr auto; gap: var(--gap-lg); align-items: baseline;
  padding: 22px 0; border-bottom: 1px solid var(--border); text-decoration: none;
  transition: background .15s ease;
}
.article-row:hover { background: var(--surface); }
.article-row > * { padding-inline: 4px; }
.article-row .topic { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.05em; text-transform: uppercase; color: var(--muted); }
.article-row .title { font-size: 18px; font-weight: 500; letter-spacing: -0.01em; }
.article-row .go { font-size: 14px; color: var(--muted); white-space: nowrap; }
.article-row:hover .title { text-decoration: underline; text-underline-offset: 4px; }
.article-row:hover .go { color: var(--fg); }
@media (max-width: 720px) {
  .article-row {
    grid-template-columns: 1fr auto;
    grid-template-areas: "topic date" "title title";
    gap: 6px var(--gap-md);
    align-items: start;
  }
  .article-row .topic { grid-area: topic; }
  .article-row .go { grid-area: date; display: block; }
  .article-row .title { grid-area: title; }
}

/* contact ---------------------------------------------------------------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--gap-xl); align-items: start; }
@media (max-width: 920px) { .contact-grid { grid-template-columns: 1fr; gap: var(--gap-lg); } }
.contact-block { border-top: 1px solid var(--border); padding-top: 20px; }
.contact-block .meta { display: block; margin-bottom: 10px; }
.contact-block p { font-size: 17px; }

/* footer ----------------------------------------------------------------- */
.pagefoot { padding-block: var(--gap-xl) var(--gap-lg); border-top: 1px solid var(--border); }
.foot-grid { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: var(--gap-lg) var(--gap-xl); align-items: start; }
.pagefoot .brand img { height: 20px; width: auto; margin-bottom: 14px; }
.pagefoot p { font-size: 13px; color: var(--muted); max-width: 44ch; }
.foot-links { display: grid; grid-template-columns: repeat(2, max-content); gap: 10px var(--gap-xl); }
.foot-links a { font-size: 14px; color: var(--muted); text-decoration: none; }
.foot-links a:hover { color: var(--fg); text-decoration: underline; text-underline-offset: 4px; }
.foot-bar { display: flex; justify-content: space-between; align-items: baseline; gap: var(--gap-sm) var(--gap-lg); flex-wrap: wrap;
  margin-top: var(--gap-xl); padding-top: var(--gap-md); border-top: 1px solid var(--border); }
.foot-bar p { font-size: 12px; max-width: none; }
.foot-bar .foot-note { max-width: 62ch; text-align: right; }
@media (max-width: 720px) {
  .foot-grid { grid-template-columns: 1fr; }
  .foot-bar { flex-direction: column; }
  .foot-bar .foot-note { text-align: left; }
}

/* page header (sub-pages) ----------------------------------------------- */
.pagehead { padding-block: clamp(44px, 6.5vw, 84px); }
.breadcrumb {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--muted); margin: 0 0 var(--gap-md);
}
.breadcrumb a { text-decoration: none; }
.breadcrumb a:hover { color: var(--fg); text-decoration: underline; text-underline-offset: 4px; }
.breadcrumb .sep { margin: 0 8px; color: var(--border); }
.pagehead h1 { max-width: 18ch; }
.pagehead .lead { margin-top: var(--gap-md); }
.pagehead .hero-cta { margin-top: var(--gap-lg); }

/* capability page -------------------------------------------------------- */
.class-block { padding-top: var(--gap-xl); }
.class-block + .class-block { border-top: 1px solid var(--border); margin-top: var(--gap-xl); }
.class-head { display: flex; justify-content: space-between; align-items: baseline; gap: var(--gap-md); flex-wrap: wrap; margin-bottom: var(--gap-md); }
.mol-table { width: 100%; min-width: 460px; border-collapse: collapse; }
.table-scroll { overflow-x: auto; }
.mol-table th, .mol-table td { text-align: left; padding: 15px 12px 15px 0; border-bottom: 1px solid var(--border); }
.mol-table th { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); font-weight: 500; }
.mol-table td.name { font-size: 17px; }
.mol-table td.stage { font-family: var(--font-mono); font-size: 12.5px; color: var(--muted); }
.mol-table td.link { text-align: right; white-space: nowrap; }
.mol-table a { color: inherit; text-decoration: none; }
.mol-table td.name a:hover { text-decoration: underline; text-underline-offset: 4px; }
.mol-table a.answer { font-size: 14px; font-weight: 500; }
.mol-table a.answer:hover { text-decoration: underline; text-underline-offset: 4px; }
.mol-table tbody tr:hover td { background: var(--surface); }

/* key / value list ------------------------------------------------------- */
.kv { list-style: none; margin: 0; padding: 0; }
.kv li { display: flex; gap: var(--gap-lg); padding: 15px 0; border-bottom: 1px solid var(--border); }
.kv .k { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); min-width: 200px; flex: none; }
.kv .v { font-size: 16px; }
@media (max-width: 560px) { .kv li { flex-direction: column; gap: 4px; } .kv .k { min-width: 0; } }

/* cta strip -------------------------------------------------------------- */
.cta-strip { text-align: center; }
.cta-strip h2 { max-width: 20ch; margin-inline: auto; }
.cta-strip .lead { margin: var(--gap-md) auto var(--gap-lg); }
.cta-strip .cta-actions { display: flex; gap: var(--gap-sm); justify-content: center; flex-wrap: wrap; }

/* two-column answer layout ---------------------------------------------- */
.answer-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: var(--gap-xl); align-items: start; }
@media (max-width: 980px) { .answer-grid { grid-template-columns: 1fr; gap: var(--gap-lg); } }

/* nav current page ------------------------------------------------------- */
.primary-nav a[aria-current="page"] { color: var(--fg); font-weight: 500; }

/* links inside capability cards ----------------------------------------- */
.cap-card h3 a { color: inherit; text-decoration: none; }
.cap-card h3 a:hover { text-decoration: underline; text-underline-offset: 4px; }
.cap-list a { color: inherit; text-decoration: none; }
.cap-list a:hover { text-decoration: underline; text-underline-offset: 4px; }

/* about / team ----------------------------------------------------------- */
.team-card { border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 28px; background: var(--bg); }
.team-card .role { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.team-card h3 { margin: 14px 0 6px; }
.team-card p { font-size: 15px; color: var(--muted); }

/* research page ---------------------------------------------------------- */
.figure { margin: 0; border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; background: var(--bg); }
.figure img { width: 100%; height: auto; }
.figure figcaption { padding: 12px 18px; border-top: 1px solid var(--border); font-family: var(--font-mono); font-size: 11.5px; color: var(--muted); }
.logo-strip { display: flex; flex-wrap: wrap; align-items: center; gap: var(--gap-xl); }
.logo-strip img { height: 34px; width: auto; }
.logo-strip img.tall { height: 46px; }
.section-note { font-family: var(--font-mono); font-size: 11.5px; color: var(--muted); margin-top: var(--gap-lg); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}