/* ───────────────────────────────────────────────────────────
   Markovian Systems — single page site
   Tokens → base → layout → components → responsive
   ─────────────────────────────────────────────────────────── */

:root {
  /* Light palette, drawn from the wordmark: warm paper, ink #201e1d, grey #7d7979 */
  --bg:          #faf8f5;
  --bg-alt:      #f3f0ea;
  --surface:     #ffffff;
  --ink:         #201e1d;
  --ink-2:       #4c4745;
  --muted:       #7d7979;
  --line:        rgba(32, 30, 29, 0.13);
  --line-strong: rgba(32, 30, 29, 0.26);
  --accent:      #3f6b52;
  --accent-ink:  #ffffff;
  --accent-soft: rgba(63, 107, 82, 0.10);
  --logo-filter: none;
  --shadow:      0 1px 2px rgba(32, 30, 29, 0.05), 0 12px 32px -18px rgba(32, 30, 29, 0.35);

  --serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  --shell: 1120px;
  --gutter: clamp(1.25rem, 5vw, 3rem);
  --radius: 14px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:          #141312;
    --bg-alt:      #1a1817;
    --surface:     #1e1c1a;
    --ink:         #f2efea;
    --ink-2:       #c7c1ba;
    --muted:       #948d87;
    --line:        rgba(242, 239, 234, 0.14);
    --line-strong: rgba(242, 239, 234, 0.28);
    --accent:      #8fc3a4;
    --accent-ink:  #12201a;
    --accent-soft: rgba(143, 195, 164, 0.13);
    --logo-filter: invert(1) brightness(1.08);
    --shadow:      0 1px 2px rgba(0, 0, 0, 0.4), 0 14px 36px -20px rgba(0, 0, 0, 0.8);
  }
}

:root[data-theme="dark"] {
  --bg:          #141312;
  --bg-alt:      #1a1817;
  --surface:     #1e1c1a;
  --ink:         #f2efea;
  --ink-2:       #c7c1ba;
  --muted:       #948d87;
  --line:        rgba(242, 239, 234, 0.14);
  --line-strong: rgba(242, 239, 234, 0.28);
  --accent:      #8fc3a4;
  --accent-ink:  #12201a;
  --accent-soft: rgba(143, 195, 164, 0.13);
  --logo-filter: invert(1) brightness(1.08);
  --shadow:      0 1px 2px rgba(0, 0, 0, 0.4), 0 14px 36px -20px rgba(0, 0, 0, 0.8);
}

/* ── Base ─────────────────────────────────────────────────── */

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.015em;
  margin: 0;
  text-wrap: balance;
}

h1 { font-size: clamp(2.3rem, 6.2vw, 4rem); }
h2 { font-size: clamp(1.75rem, 3.6vw, 2.6rem); }
h3 { font-size: 1.1875rem; line-height: 1.3; letter-spacing: -0.01em; }

p { margin: 0; }

a { color: inherit; }

img { max-width: 100%; height: auto; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--ink);
  color: var(--bg);
  padding: 0.75rem 1.25rem;
  font-size: 0.875rem;
}
.skip-link:focus { left: 0; }

.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.eyebrow {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.section-intro {
  color: var(--ink-2);
  font-size: 1.0625rem;
  max-width: 62ch;
}

/* ── Header ───────────────────────────────────────────────── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding-block: 0.875rem;
}

.brand { display: inline-flex; line-height: 0; }
.brand img {
  width: auto;
  height: 34px;
  filter: var(--logo-filter);
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--ink-2);
  text-decoration: none;
  padding-block: 0.25rem;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.nav a:hover { color: var(--ink); border-bottom-color: var(--line-strong); }
.nav a.is-active { color: var(--ink); border-bottom-color: var(--accent); }

.nav .nav-cta {
  background: var(--ink);
  color: var(--bg);
  border: 1px solid var(--ink);
  border-radius: 999px;
  padding: 0.45rem 1.1rem;
  transition: opacity 0.18s ease;
}
.nav .nav-cta:hover { opacity: 0.86; border-bottom-color: var(--ink); color: var(--bg); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 38px;
  padding: 0 9px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 10px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  height: 1.5px;
  background: var(--ink);
  transition: transform 0.22s ease, opacity 0.22s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ── Hero ─────────────────────────────────────────────────── */

.hero {
  position: relative;
  padding-block: clamp(4.5rem, 12vw, 9rem) clamp(2rem, 5vw, 3.5rem);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -40% 40% 40% -20%;
  background: radial-gradient(60% 60% at 40% 60%, var(--accent-soft), transparent 70%);
  pointer-events: none;
}

.hero .shell { position: relative; }

.hero h1 { margin-top: 1.25rem; max-width: 17ch; }

.hero .lede {
  margin-top: 1.5rem;
  max-width: 58ch;
  font-size: clamp(1.0625rem, 1.6vw, 1.1875rem);
  color: var(--ink-2);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2.25rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 1.6rem;
  border-radius: 999px;
  font-size: 0.9375rem;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.18s ease, opacity 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}
.btn:hover { transform: translateY(-1px); }

.btn-primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn-primary:hover { opacity: 0.92; }

.btn-ghost { border-color: var(--line-strong); color: var(--ink); }
.btn-ghost:hover { background: var(--surface); border-color: var(--ink); }

.hero-domains {
  display: flex;
  flex-wrap: wrap;
  gap: 0 2rem;
  margin: 3.5rem 0 0;
  padding: 1.25rem 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ── Sections ─────────────────────────────────────────────── */

.section { padding-block: clamp(4rem, 9vw, 7rem); }
.section-alt { background: var(--bg-alt); border-block: 1px solid var(--line); }

.section-head { max-width: 72ch; }
.section-head h2 { margin-top: 0.9rem; }
.section-head .section-intro { margin-top: 1.1rem; }

/* ── Capabilities ─────────────────────────────────────────── */

.capabilities {
  list-style: none;
  margin: clamp(2.5rem, 5vw, 4rem) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.capability {
  display: grid;
  grid-template-columns: 5rem 1fr;
  gap: 1.5rem;
  padding-block: clamp(1.75rem, 3.5vw, 2.5rem);
  border-bottom: 1px solid var(--line);
}

.capability-index {
  font-family: var(--serif);
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  padding-top: 0.3rem;
}

.capability-body { max-width: 66ch; }
.capability-body p { margin-top: 0.7rem; color: var(--ink-2); }

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.1rem 0 0;
  padding: 0;
  list-style: none;
}
.tags li {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.25rem 0.75rem;
  background: var(--surface);
}

/* ── Stack ────────────────────────────────────────────────── */

.stack {
  margin-top: clamp(2.5rem, 5vw, 3.5rem);
  display: grid;
  gap: 1rem;
}

.stack-layer {
  position: relative;
  display: grid;
  grid-template-columns: 8.5rem 1fr;
  gap: 1.5rem;
  align-items: start;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(1.25rem, 3vw, 1.75rem);
}

/* connector between layers */
.stack-layer:not(:last-child)::after {
  content: "";
  position: absolute;
  left: clamp(1.25rem, 3vw, 1.75rem);
  bottom: -1rem;
  width: 1px;
  height: 1rem;
  background: var(--line-strong);
}

.stack-label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  padding-top: 0.2rem;
}

.stack-content p { margin-top: 0.5rem; color: var(--ink-2); max-width: 60ch; }

/* ── Research ─────────────────────────────────────────────── */

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2rem, 6vw, 4.5rem);
  align-items: start;
}

.split-main h2 { margin-top: 0.9rem; }
.split-main .section-intro { margin-top: 1.1rem; }
.split-main .btn { margin-top: 1.75rem; }

.partners {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.partners li { background: var(--bg); padding: 1.4rem; }
.partners p { margin-top: 0.4rem; font-size: 0.9rem; color: var(--muted); }

/* ── Education ────────────────────────────────────────────── */

.programmes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: clamp(2.5rem, 5vw, 3.5rem);
}

.programme {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.6rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.programme:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.programme p { margin-top: 0.6rem; color: var(--ink-2); font-size: 0.9375rem; }

.audiences {
  display: flex;
  flex-wrap: wrap;
  gap: 0 2rem;
  margin: 2rem 0 0;
  padding: 1.25rem 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ── Contact ──────────────────────────────────────────────── */

.contact-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 6px);
  padding: clamp(2rem, 6vw, 4rem);
  box-shadow: var(--shadow);
}
.contact-card h2 { margin-top: 0.9rem; }
.contact-card .section-intro { margin-top: 1.1rem; }

.contact-email {
  margin-top: 2rem;
  font-family: var(--serif);
  font-size: clamp(1.25rem, 3.4vw, 1.9rem);
}
.contact-email a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--accent);
  padding-bottom: 2px;
  transition: color 0.18s ease;
}
.contact-email a:hover { color: var(--accent); }

/* ── Footer ───────────────────────────────────────────────── */

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--bg-alt);
  padding-block: clamp(2.5rem, 5vw, 3.5rem);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 2rem 3rem;
  align-items: start;
}

.footer-brand img {
  width: auto;
  height: 34px;
  filter: var(--logo-filter);
}
.footer-brand p {
  margin-top: 0.9rem;
  max-width: 40ch;
  font-size: 0.9rem;
  color: var(--muted);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  justify-content: flex-end;
}
.footer-nav a {
  font-size: 0.9rem;
  color: var(--ink-2);
  text-decoration: none;
}
.footer-nav a:hover { color: var(--ink); text-decoration: underline; }

.footer-legal {
  grid-column: 1 / -1;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  font-size: 0.8125rem;
  color: var(--muted);
}

/* ── Reveal animation ─────────────────────────────────────── */

/* Content is visible by default; the hidden start state is opted into by
   site.js, so a blocked or failed script can never leave the page blank. */
.js-reveal .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.js-reveal .reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .js-reveal .reveal { opacity: 1; transform: none; transition: none; }
  .btn:hover, .programme:hover { transform: none; }
}

/* ── Responsive ───────────────────────────────────────────── */

@media (max-width: 860px) {
  .split { grid-template-columns: minmax(0, 1fr); }
  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-nav { justify-content: flex-start; }
}

@media (max-width: 720px) {
  .nav-toggle { display: flex; }

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.5rem var(--gutter) 1.25rem;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
  }
  .nav:not(.is-open) { display: none; }
  .nav a {
    padding-block: 0.8rem;
    border-bottom: 1px solid var(--line);
    font-size: 1rem;
  }
  .nav .nav-cta {
    margin-top: 0.9rem;
    border-radius: 999px;
    text-align: center;
    border-bottom: 1px solid var(--ink);
  }

  .site-header { position: relative; }

  .capability { grid-template-columns: minmax(0, 1fr); gap: 0.5rem; }
  .capability-index { padding-top: 0; }

  .stack-layer { grid-template-columns: minmax(0, 1fr); gap: 0.6rem; }
  .stack-label { padding-top: 0; }

  .partners { grid-template-columns: minmax(0, 1fr); }

  .hero-domains, .audiences { gap: 0.35rem 1.25rem; }
}