/* CONVEA website — tokens follow the CONVEA Design System (tokens/colors.css,
   tokens/typography.css). Steel carries surfaces and text; signal blue is
   rationed to links and primary actions; image data sits on dark plates. */

@font-face { font-family: "Jost"; font-weight: 300; font-style: normal; font-display: swap;
  src: url("assets/fonts/jost-latin-300-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Sans"; font-weight: 400; font-style: normal; font-display: swap;
  src: url("assets/fonts/ibm-plex-sans-latin-400-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Sans"; font-weight: 500; font-style: normal; font-display: swap;
  src: url("assets/fonts/ibm-plex-sans-latin-500-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Sans"; font-weight: 600; font-style: normal; font-display: swap;
  src: url("assets/fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-weight: 400; font-style: normal; font-display: swap;
  src: url("assets/fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-weight: 500; font-style: normal; font-display: swap;
  src: url("assets/fonts/ibm-plex-mono-latin-500-normal.woff2") format("woff2"); }

:root {
  /* steel */
  --slate-990: #080b10; --slate-900: #131922; --slate-800: #222a35; --slate-650: #3f4b5c;
  --slate-600: #536176; --slate-500: #74808e; --slate-400: #939aa5; --slate-300: #adb6c1; --slate-200: #cbd3dd;
  --slate-150: #dde3ea; --slate-100: #e9edf2; --slate-50: #f3f6f9; --white: #ffffff;
  /* signal blue */
  --accent-800: #123f7d; --accent-700: #1a4f9c; --accent-600: #215baf; --accent-500: #3a72c4;

  --bg-page: var(--slate-50);
  --surface-card: var(--white);
  --plate: var(--slate-990);
  --text-strong: var(--slate-800);
  --text-body: var(--slate-650);
  --text-muted: var(--slate-600);
  --text-faint: var(--slate-500);
  --border: var(--slate-150);
  --link: var(--accent-700);

  --font-display: "Jost", Futura, "Century Gothic", system-ui, sans-serif;
  --font-ui: "IBM Plex Sans", -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SF Mono", monospace;

  --max: 1120px;
  --gutter: clamp(16px, 4vw, 40px);
  --section: clamp(72px, 10vw, 128px);
  --radius: 6px;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg-page);
  color: var(--text-body);
  font: 400 16px/1.62 var(--font-ui);
  -webkit-font-smoothing: antialiased;
}

img, video { display: block; max-width: 100%; height: auto; }

a { color: var(--link); text-underline-offset: 3px; }
a:hover { color: var(--accent-800); }
:focus-visible { outline: 2px solid var(--accent-500); outline-offset: 3px; border-radius: 2px; }

h1, h2, h3 { color: var(--text-strong); margin: 0; }
p { margin: 0; }
p + p { margin-top: 1em; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 var(--gutter); }

.display {
  font-family: var(--font-display);
  font-weight: 300;
  letter-spacing: 0.02em;
  line-height: 1.1;
}

.eyebrow {
  display: block;
  font: 500 11.5px/1 var(--font-mono);
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.lead { font-size: 19px; line-height: 1.55; color: var(--text-strong); }
.prose { max-width: 62ch; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 0.5em;
  padding: 12px 20px;
  border-radius: var(--radius);
  font: 500 15px/1 var(--font-ui);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color .15s, border-color .15s, color .15s;
}
.btn--primary { background: var(--accent-600); color: var(--white); }
.btn--primary:hover { background: var(--accent-700); color: var(--white); }
.btn--secondary { border-color: var(--slate-200); color: var(--text-strong); background: var(--white); }
.btn--secondary:hover { border-color: var(--slate-300); color: var(--text-strong); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }

/* ---------- header ---------- */
.site-header { padding: 20px 0; }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.site-header .logo img { height: 72px; width: auto; }
.site-header nav a { font-weight: 500; font-size: 15px; text-decoration: none; }

/* main page: fixed header, full size at the top, compact once scrolled.
   main reserves the full header height, so shrinking never shifts content. */
:root { --header-h: 113px; }
html { scroll-padding-top: 76px; }
.site-header--fixed {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  border-bottom: 1px solid transparent;
  transition: padding .25s ease, background-color .25s ease, border-color .25s ease;
}
.site-header--fixed + main { padding-top: var(--header-h); }
.site-header--fixed .logo img { transition: height .25s ease; }
.site-header--fixed nav a { border-radius: var(--radius); transition: background-color .25s ease, color .25s ease, padding .25s ease; }
.site-header--fixed.is-compact {
  padding: 10px 0;
  background: rgba(243, 246, 249, 0.92);
  -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px);
  border-bottom-color: var(--border);
}
.site-header--fixed.is-compact .logo img { height: 40px; }
.site-header--fixed.is-compact nav a { background: var(--accent-600); color: var(--white); padding: 8px 14px; }
.site-header--fixed.is-compact nav a:hover { background: var(--accent-700); }
@media (prefers-reduced-motion: reduce) {
  .site-header--fixed, .site-header--fixed .logo img, .site-header--fixed nav a { transition: none; }
}

/* ---------- hero ---------- */
.hero { padding: clamp(32px, 6vw, 72px) 0 clamp(56px, 8vw, 96px); }
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
}
.hero h1 { font-size: clamp(40px, 5.4vw, 68px); }
.hero .lead { margin-top: 28px; }
.hero .prose { margin-top: 16px; }
.hero-figure { margin: 0; }
.hero-figure img { width: 100%; max-width: 460px; margin-left: auto; }

/* ---------- triad (Connect · Compare · Change) ---------- */
.triad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin-top: clamp(56px, 8vw, 96px);
  border-top: 1px solid var(--border);
  padding-top: 32px;
}
.triad > div { padding: 0 24px; border-left: 1px solid var(--border); }
.triad > div:first-child { padding-left: 0; border-left: 0; }
.triad h2 {
  font: 300 clamp(24px, 2.4vw, 32px)/1.1 var(--font-display);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-600);
}
.triad p { margin-top: 12px; }

/* ---------- sections ---------- */
section { padding: var(--section) 0; }
section + section, .hero + section { border-top: 1px solid var(--border); }
section h2 { font-size: clamp(30px, 3.6vw, 44px); max-width: 24ch; }
section h2 + * { margin-top: 28px; }

.problem { display: grid; grid-template-columns: 1fr 1fr; gap: 40px clamp(32px, 6vw, 96px); align-items: start; }
.problem h2 + p { margin-top: 28px; }
.keylist { list-style: none; padding: 0; margin: 20px 0 28px; border-bottom: 1px solid var(--slate-200); }
.keylist li { padding: 18px 0 18px 28px; position: relative; border-top: 1px solid var(--slate-200); color: var(--text-strong); }
.keylist li::before { content: "→"; position: absolute; left: 0; color: var(--accent-600); font-family: var(--font-mono); }

.columns { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(24px, 4vw, 48px); margin-top: 48px; }
.columns h3 { font-size: 18px; font-weight: 600; }
.columns p { margin-top: 8px; font-size: 15px; color: var(--text-muted); }

/* dark plate for image data */
.plate { margin: 56px 0 0; }
.plate video, .plate img { width: 100%; background: var(--plate); border-radius: var(--radius); }
.plate figcaption { margin-top: 12px; font: 400 13px/1.5 var(--font-mono); color: var(--text-muted); }

.case-picker { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.case-picker button {
  padding: 8px 14px;
  border: 1px solid var(--slate-200);
  border-radius: 999px;
  background: var(--white);
  color: var(--text-body);
  font: 500 14px/1 var(--font-ui);
  cursor: pointer;
  transition: background-color .15s, border-color .15s, color .15s;
}
.case-picker button:hover { border-color: var(--slate-300); color: var(--text-strong); }
.case-picker button[aria-pressed="true"] { background: var(--accent-600); border-color: var(--accent-600); color: var(--white); }
.cases video { aspect-ratio: 2 / 1; }

.research { margin-top: clamp(56px, 8vw, 96px); display: grid; grid-template-columns: 1fr 1fr; gap: 24px clamp(24px, 5vw, 64px); }
.research h3 { grid-column: 1 / -1; }
.research h3 { font-size: 22px; font-weight: 500; }
.research p + p { margin-top: 1em; }
.refs { margin: 0; font-size: 13.5px; line-height: 1.5; color: var(--text-muted); }
.refs dt { font: 500 11.5px/1 var(--font-mono); letter-spacing: 0.13em; text-transform: uppercase; color: var(--text-muted); }
.refs dd { margin: 8px 0 20px; }
.refs dd:last-child { margin-bottom: 0; }
.refs i { font-style: italic; }

/* applications */
.cases { margin-top: 48px; }
.cases .plate { margin-top: 0; }
.case-lead { margin: 0 0 16px; font-size: 17px; color: var(--text-strong); }
.closing { margin-top: 56px; }
.closing p:first-child { color: var(--text-strong); font-weight: 500; }

.cta-line { margin-top: 48px; display: flex; flex-wrap: wrap; align-items: center; gap: 20px 32px; }
.cta-line .display { font-size: 28px; color: var(--text-strong); }

/* ---------- supporters ---------- */
.supporters-band { background: var(--white); border-top: 1px solid var(--border); padding: 48px 0; }
.logo-row { list-style: none; padding: 0; margin: 20px 0 0; display: flex; flex-wrap: wrap; align-items: center; gap: 24px 36px; }
.logo-row img { display: block; }
.supporters-grid { display: grid; grid-template-columns: 1fr auto; gap: 32px 48px; align-items: center; }
.supporters-band .funding { width: 480px; max-width: 100%; height: auto; }

/* ---------- footer ---------- */
.site-footer { background: var(--slate-900); color: var(--slate-300); padding: var(--section) 0 40px; font-size: 15px; }
.site-footer a { color: var(--slate-100); }
.site-footer a:hover { color: var(--white); }
.site-footer .claim { font-size: clamp(28px, 3.4vw, 40px); color: var(--white); max-width: 22ch; }
.footer-grid { margin-top: 56px; }
.footer-grid h3 { font-size: 16px; font-weight: 600; color: var(--white); }
.footer-grid p { margin-top: 6px; }
.footer-bottom {
  margin-top: 64px; padding-top: 24px; border-top: 1px solid rgba(173, 182, 193, 0.18);
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 24px;
  font: 400 13px/1.5 var(--font-mono); color: var(--slate-400);
}
.footer-bottom nav { display: flex; flex-wrap: wrap; gap: 8px 20px; }

.site-footer--compact { padding-top: 32px; }
.site-footer--compact .footer-bottom { margin-top: 0; padding-top: 0; border-top: 0; }

/* ---------- legal pages ---------- */
.legal { padding: 48px 0 var(--section); }
.legal .wrap { max-width: 760px; }
.legal h1 { font-size: 40px; margin-bottom: 32px; }
.legal h2 { font-size: 20px; font-weight: 600; margin: 40px 0 12px; max-width: none; }
.legal p, .legal li { font-size: 15.5px; }
.legal ul { padding-left: 1.2em; }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-figure { order: -1; }
  .hero-figure img { max-width: 240px; margin: 0 auto; }
  .research, .problem, .supporters-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .triad, .columns { grid-template-columns: 1fr; gap: 24px; }
  .triad > div { padding: 0; border-left: 0; }
  .site-header .logo img { height: 48px; }
  :root { --header-h: 89px; }
  .site-header--fixed.is-compact .logo img { height: 32px; }
  /* supporters: centred, logos in two balanced rows (3 + 2) */
  .supporters-grid { justify-items: center; text-align: center; }
  .logo-row { justify-content: center; gap: 20px 28px; max-width: 260px; margin-left: auto; margin-right: auto; }
  .logo-row { gap: 20px 32px; }
}
.legal .stand { margin-top: 40px; color: var(--text-muted); }

/* demo videos: no native controls, tap/click toggles playback */
video.autoplay { cursor: pointer; }

/* reveal on scroll (classes set by script; without JS nothing is hidden) */
.js .reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.js .reveal.is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .js .reveal { opacity: 1; transform: none; transition: none; }
}