:root {
  --ink: #071522;
  --ink-2: #0d2030;
  --panel: #102637;
  --line: rgba(145, 181, 205, .18);
  --muted: #89a0b2;
  --text: #dce8ef;
  --white: #f7fbfd;
  --blue: #5da9d6;
  --green: #72c69b;
  --gold: #d6b86d;
  --danger: #e27474;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font-family: "Inter", system-ui, sans-serif;
  font-size: 15px;
  line-height: 1.65;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.container { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }
.eyebrow {
  margin: 0 0 14px;
  color: var(--blue);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
}
.muted { color: var(--muted); }
.green { color: var(--green); }
.blue { color: var(--blue); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(7, 21, 34, .92);
  backdrop-filter: blur(18px);
}
.header-inner {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}
.brand { display: flex; align-items: center; gap: 13px; }
.brand-mark {
  width: 34px;
  height: 34px;
  border: 1px solid rgba(93,169,214,.55);
  display: grid;
  place-items: center;
  color: var(--blue);
  font-family: "IBM Plex Mono", monospace;
  font-weight: 600;
}
.brand-name { display: block; color: var(--white); font-weight: 700; letter-spacing: .01em; }
.brand-parent { display: block; color: var(--muted); font-size: 9px; letter-spacing: .15em; text-transform: uppercase; }
.nav { display: flex; align-items: center; gap: 30px; }
.nav a {
  color: #aebfcb;
  font-size: 13px;
  transition: color .2s ease;
}
.nav a:hover, .nav a[aria-current="page"] { color: var(--white); }
.nav a[aria-current="page"] { position: relative; }
.nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -30px;
  height: 2px;
  background: var(--blue);
}
.menu-button { display: none; background: transparent; border: 1px solid var(--line); color: var(--white); padding: 8px 10px; }

.hero { padding: 92px 0 72px; border-bottom: 1px solid var(--line); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(320px, .65fr); gap: 68px; align-items: end; }
h1, h2, h3, p { margin-top: 0; }
h1 {
  max-width: 850px;
  margin-bottom: 28px;
  color: var(--white);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(48px, 6vw, 78px);
  font-weight: 600;
  letter-spacing: -.045em;
  line-height: 1.02;
}
.hero-copy { max-width: 780px; color: #afc0cb; font-size: 18px; line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border: 1px solid var(--blue);
  background: var(--blue);
  color: #06131d;
  font-size: 13px;
  font-weight: 700;
  transition: transform .2s, background .2s;
}
.button:hover { transform: translateY(-2px); background: #77b9dd; }
.button.secondary { background: transparent; color: var(--text); border-color: var(--line); }
.button.secondary:hover { border-color: var(--blue); background: rgba(93,169,214,.06); }
.research-proof {
  position: relative;
  border: 1px solid var(--line);
  background: linear-gradient(145deg, rgba(16,38,55,.86), rgba(9,25,38,.9));
  padding: 28px;
}
.research-proof::before { content: ""; position: absolute; inset: 0 0 auto; height: 2px; background: linear-gradient(90deg, var(--green), transparent); }
.proof-label { color: var(--muted); font: 600 10px/1.4 "IBM Plex Mono", monospace; letter-spacing: .13em; text-transform: uppercase; }
.proof-title { margin: 12px 0 26px; color: var(--white); font-family: "Source Serif 4", serif; font-size: 27px; line-height: 1.2; }
.proof-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--line); border: 1px solid var(--line); }
.proof-stat { background: var(--ink-2); padding: 18px; }
.proof-stat strong { display: block; color: var(--white); font: 600 23px/1.2 "IBM Plex Mono", monospace; }
.proof-stat span { color: var(--muted); font-size: 11px; }

.section { padding: 78px 0; border-bottom: 1px solid var(--line); }
.section-heading { display: grid; grid-template-columns: .65fr 1.35fr; gap: 60px; margin-bottom: 42px; align-items: start; }
.section-heading h2, .page-intro h1 {
  margin: 0;
  color: var(--white);
  font-family: "Source Serif 4", serif;
  font-size: clamp(34px, 4vw, 52px);
  line-height: 1.1;
  letter-spacing: -.025em;
}
.section-heading p { max-width: 670px; color: var(--muted); font-size: 16px; }
.signal-flow { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); }
.signal {
  min-height: 250px;
  padding: 26px;
  border-right: 1px solid var(--line);
  background: rgba(13,32,48,.55);
}
.signal:last-child { border-right: 0; }
.signal-number { color: var(--blue); font: 600 11px "IBM Plex Mono", monospace; }
.signal h3 { margin: 50px 0 12px; color: var(--white); font-family: "Source Serif 4", serif; font-size: 24px; }
.signal p { color: var(--muted); font-size: 13px; }

.featured-grid { display: grid; grid-template-columns: 1.35fr .65fr; gap: 22px; }
.feature-card, .card {
  border: 1px solid var(--line);
  background: var(--ink-2);
}
.feature-card { padding: 40px; }
.tag { display: inline-flex; padding: 5px 8px; border: 1px solid rgba(114,198,155,.3); color: var(--green); font: 600 9px "IBM Plex Mono", monospace; letter-spacing: .1em; text-transform: uppercase; }
.feature-card h3 { max-width: 680px; margin: 28px 0 16px; color: var(--white); font: 600 clamp(30px, 4vw, 48px)/1.08 "Source Serif 4", serif; }
.feature-card .dek { max-width: 700px; color: #abc0cc; font-size: 16px; }
.feature-meta { display: flex; flex-wrap: wrap; gap: 22px; margin-top: 36px; padding-top: 22px; border-top: 1px solid var(--line); color: var(--muted); font: 500 10px "IBM Plex Mono", monospace; letter-spacing: .06em; text-transform: uppercase; }
.side-stack { display: grid; gap: 22px; }
.metric-card { padding: 26px; }
.metric-card .metric { display: block; margin: 26px 0 5px; color: var(--white); font: 600 34px "IBM Plex Mono", monospace; }
.metric-card h3 { color: var(--white); font-size: 15px; }

.coverage-grid, .library-grid, .research-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.coverage-card, .library-card, .research-card { padding: 28px; transition: transform .2s, border-color .2s; }
.coverage-card:hover, .library-card:hover, .research-card:hover { transform: translateY(-3px); border-color: rgba(93,169,214,.5); }
.coverage-card h3, .library-card h3, .research-card h3 { color: var(--white); font-family: "Source Serif 4", serif; font-size: 24px; line-height: 1.25; }
.coverage-card p, .library-card p, .research-card p { color: var(--muted); font-size: 13px; }
.card-link { display: inline-flex; margin-top: 18px; color: var(--blue); font-size: 12px; font-weight: 700; }
.card-link::after { content: " →"; margin-left: 6px; }

.page-intro { padding: 78px 0 55px; border-bottom: 1px solid var(--line); }
.page-intro h1 { max-width: 850px; font-size: clamp(44px, 6vw, 68px); }
.page-intro .lead { max-width: 800px; margin: 24px 0 0; color: #adc0cc; font-size: 17px; }
.filter-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 30px 0; }
.filter { border: 1px solid var(--line); background: transparent; color: var(--muted); padding: 9px 13px; cursor: pointer; }
.filter.active, .filter:hover { color: var(--white); border-color: var(--blue); }
.research-card .meta { color: var(--blue); font: 600 10px "IBM Plex Mono", monospace; text-transform: uppercase; letter-spacing: .08em; }
.research-card[hidden] { display: none; }
.library-card { min-height: 260px; display: flex; flex-direction: column; }
.library-card .card-link { margin-top: auto; }
.framework { display: grid; grid-template-columns: 280px 1fr; border: 1px solid var(--line); }
.framework-label { padding: 28px; border-right: 1px solid var(--line); color: var(--blue); font: 600 11px "IBM Plex Mono", monospace; text-transform: uppercase; letter-spacing: .1em; }
.framework-body { padding: 28px; }
.framework-body h3 { color: var(--white); font-family: "Source Serif 4", serif; font-size: 27px; }

.article-hero { padding: 78px 0 50px; border-bottom: 1px solid var(--line); }
.article-shell { width: min(820px, calc(100% - 40px)); margin: 0 auto; }
.article-hero h1 { max-width: 900px; font-size: clamp(44px, 6vw, 70px); }
.article-dek { max-width: 760px; margin: 24px 0 0; color: #adc0cc; font-size: 19px; line-height: 1.7; }
.article-byline { display: flex; flex-wrap: wrap; gap: 10px 24px; margin-top: 32px; padding-top: 22px; border-top: 1px solid var(--line); color: var(--muted); font: 500 11px "IBM Plex Mono", monospace; letter-spacing: .04em; text-transform: uppercase; }
.article-body { padding: 58px 0 90px; }
.article-body h2 { margin: 54px 0 18px; color: var(--white); font: 600 34px/1.2 "Source Serif 4", serif; letter-spacing: -.02em; }
.article-body h3 { margin: 34px 0 12px; color: var(--white); font-size: 19px; }
.article-body p, .article-body li { color: #bed0da; font-size: 17px; line-height: 1.85; }
.article-body ul, .article-body ol { margin: 18px 0 28px; padding-left: 24px; }
.article-body li { margin-bottom: 8px; padding-left: 6px; }
.article-body strong { color: var(--white); }
.article-body blockquote { margin: 30px 0; padding: 22px 26px; border-left: 2px solid var(--green); background: rgba(16,38,55,.62); color: var(--white); font: 600 21px/1.55 "Source Serif 4", serif; }
.article-body blockquote p { margin: 0; color: var(--white); font: inherit; }
.formula { margin: 20px 0; padding: 20px 22px; border: 1px solid var(--line); background: var(--ink-2); color: var(--green); font: 600 15px/1.65 "IBM Plex Mono", monospace; }
.article-table-wrap { margin: 30px 0; overflow-x: auto; border: 1px solid var(--line); }
.article-table { width: 100%; min-width: 620px; border-collapse: collapse; }
.article-table th, .article-table td { padding: 14px 16px; border-bottom: 1px solid var(--line); text-align: left; }
.article-table th { color: var(--blue); font: 600 10px "IBM Plex Mono", monospace; letter-spacing: .08em; text-transform: uppercase; }
.article-table td { color: #bed0da; font-size: 14px; }
.article-note { margin-top: 58px; padding-top: 24px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.original-link { display: inline-flex; margin-top: 20px; color: var(--blue); font-weight: 700; font-size: 13px; }

.footer { padding: 48px 0; }
.footer-grid { display: grid; grid-template-columns: 1fr auto; gap: 40px; align-items: end; }
.footer-title { color: var(--white); font-family: "Source Serif 4", serif; font-size: 24px; }
.footer p { margin-bottom: 5px; color: var(--muted); font-size: 11px; }
.footer-links { display: flex; gap: 22px; color: #aabcc8; font-size: 12px; }

@media (max-width: 900px) {
  .menu-button { display: block; }
  .nav { display: none; position: absolute; top: 81px; left: 0; right: 0; padding: 20px; background: var(--ink-2); border-bottom: 1px solid var(--line); flex-direction: column; align-items: flex-start; }
  .nav.open { display: flex; }
  .nav a[aria-current="page"]::after { display: none; }
  .hero-grid, .featured-grid, .section-heading { grid-template-columns: 1fr; }
  .signal-flow { grid-template-columns: 1fr 1fr; }
  .signal:nth-child(2) { border-right: 0; }
  .signal:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
}
@media (max-width: 620px) {
  .container { width: min(100% - 28px, var(--max)); }
  .hero { padding: 62px 0 54px; }
  h1 { font-size: 43px; }
  .signal-flow, .coverage-grid, .library-grid, .research-grid, .footer-grid, .framework { grid-template-columns: 1fr; }
  .signal { min-height: auto; border-right: 0; border-bottom: 1px solid var(--line); }
  .signal h3 { margin-top: 28px; }
  .framework-label { border-right: 0; border-bottom: 1px solid var(--line); }
}