/* BridgeMD — shared stylesheet */

:root {
  --paper:        #ffffff;
  --paper-2:      #f6f5f3;
  --surface:      #faf9f7;
  --ink:          #14181d;
  --ink-2:        #454e59;
  --ink-3:        #767f8b;
  --rule:         #e4e2dd;
  --rule-2:       #d7d4cd;
  --accent:       #b5542c;
  --accent-soft:  #f7eae2;
  --bridge:       #2f5d7c;
  --bridge-soft:  #e6eef4;

  /* one colour per evaluation domain, reused by the diagram, the
     work-package badges, the use-case tiles and the snapshot pills */
  --c-ml:          #2f5d7c;
  --c-ml-soft:     #e4eef5;
  --c-mat:         #9c3a22;
  --c-mat-soft:    #f8e6e0;
  --c-plant:       #2f7049;
  --c-plant-soft:  #e2f0e7;
  --c-comm:        #6d4b86;
  --c-comm-soft:   #efe8f4;
  --c-meth:        #8a6310;
  --c-meth-soft:   #fbf0db;
  --c-integ:       #a3335f;
  --c-integ-soft:  #fae8ef;
  --tint:          #f4f6f8;

  /* panels that stay dark in both colour schemes */
  --invert-bg:     #16263a;
  --invert-fg:     #ffffff;
  --invert-fg-dim: #c4ccd6;
  --on-accent:     #ffffff;

  --font-sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;

  --wrap: 1120px;
  --gutter: 24px;
  --radius: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:       #0f1319;
    --paper-2:     #141921;
    --surface:     #171d26;
    --ink:         #eef1f5;
    --ink-2:       #bdc5d0;
    --ink-3:       #8b95a2;
    --rule:        #262e39;
    --rule-2:      #333d4a;
    --accent:      #e8926a;
    --accent-soft: #2c2018;
    --bridge:      #8cb8d6;
    --bridge-soft: #192734;
    --c-ml:         #8cb8d6;
    --c-ml-soft:    #18242f;
    --c-mat:        #e5816b;
    --c-mat-soft:   #2d1d18;
    --c-plant:      #7cc098;
    --c-plant-soft: #15251d;
    --c-comm:       #c0a2d2;
    --c-comm-soft:  #241c2c;
    --c-meth:       #e5b45c;
    --c-meth-soft:  #2a2111;
    --c-integ:      #eb9ab9;
    --c-integ-soft: #2c1a22;
    --tint:         #121923;
    --invert-bg:     #1b2a3c;
    --invert-fg:     #eef1f5;
    --invert-fg-dim: #a6b0bd;
  }
}

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

html { scroll-behavior: smooth; scroll-padding-top: 80px; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

h1, h2, h3 {
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.021em;
  color: var(--ink);
  margin: 0 0 .5em;
}
h1 { font-size: clamp(2.3rem, 6vw, 3.6rem); }
h2 { font-size: clamp(1.55rem, 3.2vw, 2.1rem); }
h3 { font-size: 1.08rem; letter-spacing: -0.012em; }

p { margin: 0 0 1em; color: var(--ink-2); }
p:last-child { margin-bottom: 0; }
.lead { font-size: 1.13rem; color: var(--ink); font-weight: 500; line-height: 1.5; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--ink); }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }
.wrap--narrow { max-width: 780px; }

.skip-link { position: absolute; left: -9999px; top: 0; background: var(--invert-bg); color: var(--invert-fg); padding: .6rem 1rem; z-index: 50; }
.skip-link:focus { left: 8px; top: 8px; }

.eyebrow {
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 .9rem;
}
.eyebrow--accent { color: var(--accent); }

/* ---------- header ---------- */

.site-header {
  position: sticky; top: 0; z-index: 40;
  background: var(--paper);
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid var(--rule);
}
.site-header__inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 62px; }

.brand {
  display: inline-flex; align-items: center; gap: .55rem;
  font-size: 1.16rem; font-weight: 700; letter-spacing: -0.02em;
  color: var(--ink); text-decoration: none;
}
.brand:hover { color: var(--ink); }
.brand__mark { flex: none; display: block; }
.brand__mark .brand__arc { stroke: var(--accent); }

.nav { display: flex; align-items: center; gap: .2rem; }
.nav a {
  display: inline-block; padding: .4rem .65rem; border-radius: 7px;
  font-size: .92rem; font-weight: 500; color: var(--ink-2); text-decoration: none;
}
.nav a:hover { background: var(--paper-2); color: var(--ink); }
.nav a[aria-current="page"] { color: var(--ink); font-weight: 600; background: var(--paper-2); }

.nav-toggle {
  display: none; align-items: center; gap: .4rem;
  background: var(--surface); border: 1px solid var(--rule); border-radius: 9px;
  color: var(--ink); font: inherit; font-size: .9rem; padding: .4rem .65rem; cursor: pointer;
}
@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .nav {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    padding: .4rem var(--gutter) .9rem;
    background: var(--paper); border-bottom: 1px solid var(--rule);
  }
  .nav[hidden] { display: none; }
  .nav a { padding: .65rem .5rem; font-size: 1rem; }
}

/* ---------- hero ---------- */

.hero {
  padding: clamp(2.5rem, 6vw, 4.5rem) 0 clamp(1rem, 2vw, 1.5rem);
  background:
    radial-gradient(900px 400px at 84% -8%, var(--c-ml-soft), transparent 68%),
    radial-gradient(760px 340px at -4% 8%, var(--c-mat-soft), transparent 62%);
}
.hero__grid {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3.5rem); align-items: center;
}
@media (max-width: 900px) { .hero__grid { grid-template-columns: 1fr; } }

.hero h1 { margin-bottom: .45rem; }
.hero__sub {
  font-size: clamp(1.08rem, 2.2vw, 1.3rem); font-weight: 500; line-height: 1.4;
  color: var(--ink-2); margin: 0 0 1.1rem; letter-spacing: -0.012em;
}

.btn-row { display: flex; flex-wrap: wrap; gap: .6rem; margin-top: 1.4rem; }
.btn {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .62rem 1.05rem; border-radius: 999px;
  font-size: .92rem; font-weight: 600; text-decoration: none;
  border: 1px solid transparent;
  transition: background .12s ease, border-color .12s ease, color .12s ease;
}
.btn--primary { background: var(--ink); color: var(--paper); }
.btn--primary:hover { background: var(--accent); color: var(--on-accent); }
.btn--ghost { border-color: var(--rule-2); color: var(--ink); background: transparent; }
.btn--ghost:hover { border-color: var(--ink-3); color: var(--ink); background: var(--paper-2); }

.hero__figure { margin: 0; }
.hero__figure svg { width: 100%; height: auto; display: block; }

.diagram { font-family: var(--font-sans); }
.diagram .d-arc { fill: none; stroke: var(--rule); stroke-width: 2; stroke-dasharray: 5 7; }
.diagram .d-card { fill: var(--surface); stroke: var(--rule-2); stroke-width: 1; }
.diagram .d-pill { fill: var(--bridge-soft); stroke: var(--rule); stroke-width: 1; }
.diagram .d-pill--mat   { fill: var(--c-mat-soft);   stroke: var(--c-mat);   stroke-opacity: .4; }
.diagram .d-pill--ml    { fill: var(--c-ml-soft);    stroke: var(--c-ml);    stroke-opacity: .4; }
.diagram .d-pill--plant { fill: var(--c-plant-soft); stroke: var(--c-plant); stroke-opacity: .4; }
.diagram .d-engine { fill: var(--invert-bg); }
.diagram .d-text { font-size: 13px; fill: var(--ink); }
.diagram .d-label { font-size: 10px; font-weight: 700; letter-spacing: 1.2px; fill: var(--ink-3); }
.diagram .d-label--center { text-anchor: middle; }
.diagram .d-engine-name { font-size: 15px; font-weight: 700; text-anchor: middle; fill: var(--invert-fg); }
.diagram .d-engine-sub { font-size: 10.5px; text-anchor: middle; fill: var(--invert-fg-dim); }
.diagram .d-links path { fill: none; stroke: var(--bridge); stroke-width: 2; }
.diagram .d-link--base  { stroke: var(--ink-3) !important; }
.diagram .d-link--mat   { stroke: var(--c-mat) !important; }
.diagram .d-link--ml    { stroke: var(--c-ml) !important; }
.diagram .d-link--plant { stroke: var(--c-plant) !important; }
.diagram .d-arrow path { fill: var(--bridge); stroke: none; }
.diagram .d-arrow--base path  { fill: var(--ink-3); }
.diagram .d-arrow--mat path   { fill: var(--c-mat); }
.diagram .d-arrow--ml path    { fill: var(--c-ml); }
.diagram .d-arrow--plant path { fill: var(--c-plant); }

/* ---------- project snapshot ---------- */

.snapshot {
  margin: clamp(2rem, 5vw, 3.5rem) 0 0;
  border: 1px solid var(--rule-2);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--rule);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
}
@media (max-width: 680px) { .snapshot { grid-template-columns: 1fr; } }

.snapshot__title {
  grid-column: 1 / -1;
  background: var(--surface);
  padding: .6rem 1.15rem;
  font-size: .68rem; font-weight: 600; letter-spacing: .13em;
  text-transform: uppercase; color: var(--ink-3);
}
.snap { background: var(--paper); padding: 1.05rem 1.15rem; }
.snap__label {
  display: block; font-size: .67rem; font-weight: 600; letter-spacing: .11em;
  text-transform: uppercase; color: var(--ink-3); margin-bottom: .35rem;
}
.snap__value { font-size: .97rem; font-weight: 600; color: var(--ink); line-height: 1.4; }
.snap__sub { font-size: .85rem; color: var(--ink-3); margin-top: .2rem; line-height: 1.45; }
.snap--wide { grid-column: 1 / -1; }
.snap__person { display: flex; align-items: center; gap: .6rem; }

/* ---------- sections ---------- */

.section { padding: clamp(2.8rem, 6vw, 4.5rem) 0; }
.section--tint { background: var(--tint); border-block: 1px solid var(--rule); }
.section__head { max-width: 720px; margin-bottom: clamp(1.6rem, 3vw, 2.4rem); }
.section__head h2 { margin-bottom: .6rem; }

.two-col {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(1.5rem, 4vw, 3rem); margin-top: 1.6rem;
}
@media (max-width: 760px) { .two-col { grid-template-columns: 1fr; gap: 1rem; } }
.two-col p { font-size: .97rem; }

/* ---------- generic card grid ---------- */

.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
@media (max-width: 900px) { .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 640px) { .grid-3, .grid-2 { grid-template-columns: 1fr; } }

.card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.3rem 1.25rem;
}
.card h3 { margin-bottom: .4rem; }
.card p { font-size: .93rem; color: var(--ink-2); }

.card__n {
  display: block; font-size: .78rem; font-weight: 700; letter-spacing: .04em;
  color: var(--accent); margin-bottom: .5rem;
}
.card__n--meth  { color: var(--c-meth); }
.card__n--integ { color: var(--c-integ); }
.card__n--mat   { color: var(--c-mat); }
.card__n--ml    { color: var(--c-ml); }
.card__n--plant { color: var(--c-plant); }

a.card { text-decoration: none; display: block; transition: border-color .12s ease; }
a.card:hover { border-color: var(--ink-3); }
a.card h3 { color: var(--ink); }

/* ---------- work-package tiles ---------- */

.wp-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
@media (max-width: 980px) { .wp-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 660px) { .wp-grid { grid-template-columns: 1fr; } }

.wp-tile {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex; flex-direction: column;
}
.wp-tile__top { display: flex; align-items: center; justify-content: space-between; gap: .75rem; margin-bottom: .9rem; }
.wp-badge {
  font-size: .72rem; font-weight: 700; letter-spacing: .06em;
  background: var(--paper); border: 1px solid var(--rule-2);
  color: var(--ink); padding: .22rem .5rem; border-radius: 6px;
}
.wp-badge--meth  { background: var(--c-meth-soft);  border-color: transparent; color: var(--c-meth); }
.wp-badge--integ { background: var(--c-integ-soft); border-color: transparent; color: var(--c-integ); }
.wp-badge--ml    { background: var(--c-ml-soft);    border-color: transparent; color: var(--c-ml); }
.wp-badge--mat   { background: var(--c-mat-soft);   border-color: transparent; color: var(--c-mat); }
.wp-badge--plant { background: var(--c-plant-soft); border-color: transparent; color: var(--c-plant); }
.wp-badge--comm  { background: var(--c-comm-soft);  border-color: transparent; color: var(--c-comm); }

.wp-out { font-size: .72rem; color: var(--ink-3); text-align: right; letter-spacing: .02em; }
.wp-tile h3 { margin-bottom: .55rem; }
.wp-tile__lead { margin-bottom: .75rem; }
.wp-tile__lead-label {
  display: block; font-size: .64rem; font-weight: 600; letter-spacing: .11em;
  text-transform: uppercase; color: var(--ink-3); margin-bottom: .1rem;
}
.wp-tile__lead-name { font-size: .85rem; color: var(--ink-2); }
.wp-tile p { font-size: .91rem; }
.wp-tile__foot {
  margin-top: auto; padding-top: .95rem;
}
.wp-tile .pills { margin-bottom: .9rem; }
.wp-tile__person {
  display: flex; align-items: center; gap: .5rem;
  padding-top: .85rem; border-top: 1px solid var(--rule);
}

.pills { display: flex; flex-wrap: wrap; gap: .35rem; margin: .9rem 0 0; padding: 0; list-style: none; }
.pill {
  font-size: .74rem; color: var(--ink-2);
  background: var(--paper); border: 1px solid var(--rule);
  border-radius: 999px; padding: .2rem .58rem; white-space: nowrap;
}
.pill--accent { background: var(--accent-soft); border-color: transparent; color: var(--accent); }
.pill--bridge { background: var(--bridge-soft); border-color: transparent; color: var(--bridge); }
.pill--ml     { background: var(--c-ml-soft);    border-color: transparent; color: var(--c-ml); }
.pill--mat    { background: var(--c-mat-soft);   border-color: transparent; color: var(--c-mat); }
.pill--plant  { background: var(--c-plant-soft); border-color: transparent; color: var(--c-plant); }

/* ---------- monogram + person chip ---------- */

.mono {
  flex: none;
  width: 26px; height: 26px; border-radius: 50%;
  display: inline-grid; place-items: center;
  background: var(--bridge-soft); color: var(--bridge);
  font-size: .64rem; font-weight: 700; letter-spacing: .02em;
}
.mono--lg { width: 38px; height: 38px; font-size: .8rem; }

.person-chip { display: flex; align-items: center; gap: .5rem; font-size: .85rem; color: var(--ink-2); }
.person-chip strong { font-weight: 600; color: var(--ink); }

/* ---------- use-case tiles ---------- */

.uc-tile { display: flex; flex-direction: column; border-top-width: 3px; border-top-style: solid; }
.uc-tile--ml    { border-top-color: var(--c-ml); }
.uc-tile--mat   { border-top-color: var(--c-mat); }
.uc-tile--plant { border-top-color: var(--c-plant); }
.uc-tile__head { display: flex; align-items: center; gap: .6rem; margin-bottom: .8rem; }
.uc-tile h3 { margin: 0; }
.uc-tile__foot { margin-top: auto; padding-top: 1rem; }

/* ---------- partners ---------- */

.partner-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .75rem; }
@media (max-width: 900px) { .partner-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px) { .partner-grid { grid-template-columns: 1fr; } }

.partner {
  display: flex; align-items: center; gap: .8rem;
  background: var(--surface); border: 1px solid var(--rule);
  border-radius: 10px; padding: .7rem .85rem;
}
/* white tile: most of these marks are dark and would vanish in dark mode */
.partner__logo {
  flex: none;
  width: 46px; height: 46px;
  display: flex; align-items: center; justify-content: center;
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 9px;
  padding: 6px;
}
/* explicit size + contain: a flex item will not shrink below its intrinsic
   size on its own, and these SVGs have no intrinsic size */
.partner__logo img { width: 100%; height: 100%; object-fit: contain; }
.partner__logo--sm { width: 34px; height: 34px; border-radius: 7px; padding: 4px; }

.partner__name { font-size: .92rem; font-weight: 600; color: var(--ink); line-height: 1.3; }
.partner__role { font-size: .79rem; color: var(--ink-3); line-height: 1.35; }

.group-label {
  font-size: .68rem; font-weight: 600; letter-spacing: .13em; text-transform: uppercase;
  color: var(--ink-3); margin: 0 0 .85rem;
}
.group + .group { margin-top: 2rem; }

/* ---------- people ---------- */

.person {
  background: var(--surface); border: 1px solid var(--rule);
  border-radius: var(--radius); padding: 1.15rem;
}
.person__top { display: flex; align-items: center; gap: .7rem; margin-bottom: .7rem; }
.person__name { font-size: .98rem; font-weight: 650; color: var(--ink); margin: 0; line-height: 1.25; }
.person__aff { font-size: .82rem; color: var(--ink-3); margin: .1rem 0 0; }
.person__role { font-size: .88rem; color: var(--ink-2); margin: 0; }

/* ---------- strip (datathon testers) ---------- */

.strip { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1px; background: var(--rule); border: 1px solid var(--rule-2); border-radius: var(--radius); overflow: hidden; }
@media (max-width: 820px) { .strip { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 480px) { .strip { grid-template-columns: 1fr; } }
.strip__cell { background: var(--paper); padding: 1.05rem 1.1rem; }
.strip__head { display: flex; align-items: center; gap: .55rem; margin-bottom: .5rem; }
.strip__who { font-size: .9rem; font-weight: 650; color: var(--ink); margin: 0; }
.strip__what { font-size: .84rem; color: var(--ink-3); margin: 0; line-height: 1.45; }

/* ---------- CTA ---------- */

.cta {
  background: var(--invert-bg); color: var(--invert-fg); border-radius: var(--radius);
  padding: clamp(1.6rem, 4vw, 2.4rem);
  display: grid; gap: 1.1rem; align-items: center;
  grid-template-columns: minmax(0, 1fr) auto;
}
@media (max-width: 720px) { .cta { grid-template-columns: 1fr; } }
.cta h2 { color: var(--invert-fg); margin-bottom: .35rem; font-size: clamp(1.3rem, 2.6vw, 1.6rem); }
.cta p { color: var(--invert-fg-dim); font-size: .95rem; }
.cta a:not(.btn) { color: var(--invert-fg); text-decoration-color: rgba(255, 255, 255, .45); }
.cta a:not(.btn):hover { text-decoration-color: var(--invert-fg); }
.cta .btn--primary { background: var(--invert-fg); color: var(--invert-bg); }
.cta .btn--primary:hover { background: var(--invert-fg); color: var(--invert-bg); opacity: .88; }

/* ---------- page head (subpage) ---------- */

.page-head { padding: clamp(2.4rem, 5vw, 3.6rem) 0 clamp(1.6rem, 3vw, 2.2rem); border-bottom: 1px solid var(--rule); }
.page-head .lead { max-width: 680px; }

/* ---------- notes ---------- */

.notes { font-size: .86rem; color: var(--ink-3); }
.notes a { color: var(--bridge); }

/* ---------- footer ---------- */

.site-footer { border-top: 1px solid var(--rule); background: var(--paper-2); padding: 2.4rem 0 1.6rem; font-size: .9rem; }
.site-footer__grid { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: 2rem; }
@media (max-width: 700px) { .site-footer__grid { grid-template-columns: 1fr; gap: 1.2rem; } }
.site-footer p { color: var(--ink-3); }
.site-footer strong { color: var(--ink); font-weight: 650; }
.site-footer ul { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: .4rem 1.2rem; }
.site-footer a { color: var(--ink-2); text-decoration: none; }
.site-footer a:hover { color: var(--accent); text-decoration: underline; }
.site-footer__bar {
  margin-top: 2rem; padding-top: 1.1rem; border-top: 1px solid var(--rule);
  color: var(--ink-3); font-size: .82rem;
  display: flex; flex-wrap: wrap; gap: .4rem 1.5rem; justify-content: space-between;
}

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