@font-face { font-family: "Saira"; font-weight: 500; font-display: swap; src: url("../fonts/saira-latin-500-normal.woff2") format("woff2"); }
@font-face { font-family: "Saira"; font-weight: 600; font-display: swap; src: url("../fonts/saira-latin-600-normal.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-weight: 400; font-display: swap; src: url("../fonts/inter-latin-400-normal.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-weight: 500; font-display: swap; src: url("../fonts/inter-latin-500-normal.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-weight: 600; font-display: swap; src: url("../fonts/inter-latin-600-normal.woff2") format("woff2"); }

/* AI4I — palette from the chair logo + Télécom Paris */
:root {
  --blue: #12a2e6;        /* AI4I logo */
  --blue-deep: #1f47e5;   /* AI4I logo gradient */
  --blue-soft: #e8f5fc;
  --red: #b50c35;         /* Télécom Paris */
  --ink: #231f20;         /* Télécom Paris */
  --muted: #5d6670;
  --line: #e3e8ee;
  --bg: #ffffff;
  --wrap: 1120px;
  --radius: 14px;
  --head: "Saira", system-ui, sans-serif;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font: 400 17px/1.65 var(--body); color: var(--ink); background: var(--bg); }
img { max-width: 100%; display: block; }
a { color: var(--blue-deep); text-decoration: none; }
a:hover { color: var(--red); }
h1, h2, h3 { font-family: var(--head); line-height: 1.15; margin: 0 0 .5em; }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 10; background: rgba(255,255,255,.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.bar { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.brand { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.brand img { height: 44px; width: auto; }
.brand-name { font: 600 24px/1 var(--head); letter-spacing: .5px; }
.brand-sub { font-size: 12px; color: var(--muted); line-height: 1.3; }
.brand:hover { color: var(--ink); }
.nav { display: flex; gap: 28px; }
.nav a { color: var(--ink); font-weight: 500; font-size: 15px; padding: 6px 0; border-bottom: 2px solid transparent; }
.nav a:hover, .nav a[aria-current] { color: var(--blue-deep); border-color: var(--red); }

/* Hero */
.hero { color: #fff; background: linear-gradient(90deg, #1ea3e6 50%, rgba(30,163,230,0) 80%), url("../img/banner.png") right center / auto 100% no-repeat, #1ea3e6; }
.hero-inner { padding: 96px 24px 104px; }
.hero h1 { font-size: clamp(40px, 6vw, 68px); font-weight: 600; letter-spacing: -.5px; }
.hero-lead { font-size: 20px; max-width: 34em; opacity: .95; }
.hero-cta { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }
.btn { display: inline-block; padding: 12px 22px; border-radius: 999px; background: #fff; color: var(--blue-deep); font-weight: 600; }
.btn:hover { color: var(--red); }
.btn.ghost { background: transparent; color: #fff; box-shadow: inset 0 0 0 2px rgba(255,255,255,.8); }
.btn.ghost:hover { background: rgba(255,255,255,.12); color: #fff; }

.eyebrow { font: 600 13px/1 var(--body); letter-spacing: .12em; text-transform: uppercase; color: var(--blue); margin: 0 0 14px; }
.eyebrow.light { color: rgba(255,255,255,.85); }

/* Sections */
section.wrap { padding-top: 72px; }
.section-title { font-size: 28px; font-weight: 600; position: relative; padding-bottom: 12px; margin-bottom: 28px; }
.section-title::after { content: ""; position: absolute; left: 0; bottom: 0; width: 40px; height: 3px; background: var(--red); }

.intro { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; color: var(--muted); }
.intro p { margin: 0; }

.axes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.axis { display: block; padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); color: var(--ink); transition: transform .2s, box-shadow .2s, border-color .2s; }
.axis:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(31,71,229,.10); border-color: var(--blue); color: var(--ink); }
.axis-num { font: 600 15px var(--head); color: var(--blue); }
.axis h3 { font-size: 22px; margin: 8px 0; }
.axis p { margin: 0; color: var(--muted); font-size: 15px; }

.links2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.links2 .link-arrow { display: inline-block; margin-top: 14px; color: var(--blue-deep); }
.link-arrow { font-weight: 600; }

.partners { margin-top: 80px; padding: 56px 0; background: var(--blue-soft); }
.logos { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 16px; }
.logo-tile { background: #fff; border-radius: var(--radius); height: 110px; display: flex; align-items: center; justify-content: center; padding: 22px; }
.logo-tile img { max-height: 56px; max-width: 140px; width: auto; height: auto; mix-blend-mode: multiply; filter: grayscale(1); opacity: .8; transition: .2s; }
.logo-tile:hover img { filter: none; opacity: 1; }

/* News */
.news-head { display: flex; justify-content: space-between; align-items: baseline; }
.news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.news-grid.compact { grid-template-columns: 1fr; gap: 12px; margin-top: 20px; }
.news-card { display: flex; flex-direction: column; gap: 6px; padding: 22px 24px; border-radius: var(--radius); background: var(--blue-soft); border-left: 4px solid var(--blue); color: var(--ink); transition: transform .2s, box-shadow .2s; }
.news-card:hover { transform: translateY(-3px); box-shadow: 0 12px 30px rgba(31,71,229,.10); color: var(--ink); }
.news-title { font: 600 18px/1.3 var(--head); }
.news-meta { font-size: 14px; color: var(--muted); }
.prose .news-card .news-title { font-size: 17px; }
.muted { color: var(--muted); }
.closed { background: #fbe9ed; color: var(--red); padding: 12px 16px; border-radius: 10px; font-weight: 500; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); padding: 36px 0; font-size: 14px; color: var(--muted); }
.partners + .site-footer, main > :last-child { margin-bottom: 0; }
.foot { display: flex; gap: 32px; align-items: center; }
.foot p { margin: 0 0 4px; }
.foot-logo { height: 56px; width: auto; }
main { min-height: 60vh; padding-bottom: 72px; }
main:has(> .partners:last-child) { padding-bottom: 0; }

/* Inner pages */
.page-head { background: linear-gradient(120deg, var(--blue-soft), #fff 70%); border-bottom: 1px solid var(--line); padding: 56px 0 40px; }
.page-head h1 { font-size: 44px; font-weight: 600; }
.page-head .lead { font-size: 19px; color: var(--muted); max-width: 40em; margin: 0; }
.prose { padding-top: 48px; max-width: 820px; margin-left: max(0px, calc((100% - var(--wrap)) / 2)); }
.prose h2 { font-size: 24px; margin-top: 1.6em; padding-left: 14px; border-left: 3px solid var(--red); scroll-margin-top: 96px; }
.cards { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.prose .cards { width: min(1072px, 100vw - 48px); }
.card { border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; }
.card h3 { font-size: 20px; }

/* Team */
.leads { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.person { font: inherit; color: inherit; text-align: left; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); cursor: pointer; transition: transform .2s, box-shadow .2s, border-color .2s; }
.person:hover, .person:focus-visible { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(31,71,229,.10); border-color: var(--blue); outline: none; }
.lead-card { display: flex; gap: 18px; align-items: center; padding: 18px; }
.lead-card img { width: 96px; height: 96px; border-radius: 50%; object-fit: cover; flex: none; }
.person-text { display: flex; flex-direction: column; gap: 4px; }
.tag { font: 600 12px var(--body); letter-spacing: .08em; text-transform: uppercase; color: var(--red); }
.person-name { font: 600 19px/1.2 var(--head); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 6px; }
.chips span { font-size: 12px; padding: 3px 9px; border-radius: 999px; background: var(--blue-soft); color: var(--blue-deep); }

.members-title { margin-top: 64px; }
.members { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 18px; }
.member-card { padding: 22px 18px; display: flex; flex-direction: column; align-items: center; text-align: center; gap: 6px; }
.member-card img { width: 120px; height: 120px; border-radius: 50%; object-fit: cover; margin-bottom: 8px; }
.member-card .person-name { font-size: 17px; }
.person-kw { font-size: 13px; color: var(--muted); line-height: 1.4; }

.juniors { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.junior { display: flex; gap: 16px; align-items: flex-start; padding: 18px 20px; border: 1px solid var(--line); border-radius: var(--radius); }
.junior p { margin: 0; }
.initials { flex: none; width: 52px; height: 52px; border-radius: 50%; background: var(--blue-soft); color: var(--blue-deep); display: flex; align-items: center; justify-content: center; font: 600 18px var(--head); }
.junior-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 10px; }
.junior-head .person-name { font-size: 17px; }
.junior-head .tag { font-size: 11px; }
.junior-topic { font-size: 15px; margin: 4px 0 !important; }
.junior-meta { font-size: 13px; color: var(--muted); }

.profile { width: min(760px, 92vw); border: 0; border-radius: 18px; padding: 36px; box-shadow: 0 30px 80px rgba(0,0,0,.25); }
.profile::backdrop { background: rgba(35,31,32,.45); backdrop-filter: blur(2px); }
.profile-body { display: grid; grid-template-columns: 140px 1fr; gap: 28px; }
.profile-body > img { width: 140px; height: 140px; border-radius: 50%; object-fit: cover; }
.profile h3 { font-size: 26px; margin: 0; }
.profile .role { color: var(--red); font-weight: 500; margin: 4px 0 12px; }
.profile .bio { font-size: 15px; color: var(--muted); }
.profile .bio p { margin: 0 0 .8em; }
.close { position: absolute; top: 14px; right: 18px; border: 0; background: none; font-size: 28px; cursor: pointer; color: var(--muted); }

/* Mobile */
@media (max-width: 820px) {
  .bar { height: auto; flex-wrap: wrap; gap: 4px 16px; padding: 10px 24px; }
  .nav { gap: 16px; } .nav a { font-size: 14px; }
  .brand img { height: 36px; } .brand-sub { display: none; }
  .intro, .axes, .links2, .news-grid, .juniors, .leads, .cards, .profile-body { grid-template-columns: 1fr; }
  .hero { background-size: cover; }
  .hero-inner { padding: 64px 24px; }
  .prose .cards { width: auto; }
  .foot { flex-direction: column; align-items: flex-start; }
}