:root {
  --ink: #172329;
  --muted: #5f6e72;
  --paper: #f7f8f5;
  --card: #ffffff;
  --line: #dfe6e3;
  --accent: #0e766e;
  --accent-dark: #095951;
  --accent-soft: #e7f2ef;
  --warm: #c76d3a;
  --shadow: 0 18px 50px rgba(21, 46, 45, .07);
  --radius: 18px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 6rem;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 2%, rgba(14, 118, 110, .08), transparent 24rem),
    var(--paper);
  font: 16px/1.68 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a {
  color: var(--accent-dark);
  text-decoration-thickness: .08em;
  text-underline-offset: .18em;
}

a:hover { color: var(--warm); }

.site-header {
  position: sticky;
  z-index: 10;
  top: 0;
  border-bottom: 1px solid rgba(223, 230, 227, .9);
  background: rgba(247, 248, 245, .88);
  backdrop-filter: blur(14px);
}

.header-inner,
main,
footer {
  width: min(1120px, calc(100% - 40px));
  margin-inline: auto;
}

.header-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .8rem;
  color: var(--ink);
  font-weight: 750;
  letter-spacing: -.02em;
  text-decoration: none;
}

.brand img { width: 42px; height: 42px; }

.header-logos {
  display: flex;
  align-items: center;
  gap: clamp(.7rem, 2vw, 1.6rem);
}

.header-logos a {
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
}

.header-logos img {
  display: block;
  max-width: 130px !important;
  max-height: 54px !important;
  object-fit: contain;
}

.header-logos .header-logo-lis { width: 68px !important; height: 54px !important; }
.header-logos .header-logo-univ { width: 130px !important; height: 34px !important; }
.header-logos .header-logo-geii { width: 115px !important; height: 38px !important; }

.hero {
  position: relative;
  padding: clamp(5rem, 11vw, 9rem) 0 clamp(3.5rem, 8vw, 6rem);
  border-bottom: 1px solid var(--line);
}

.hero::after {
  content: "";
  position: absolute;
  right: 3%;
  top: 18%;
  width: min(28vw, 290px);
  aspect-ratio: 1;
  border: 1px solid rgba(14, 118, 110, .17);
  border-radius: 50%;
  box-shadow: inset 0 0 0 28px var(--paper), inset 0 0 0 29px rgba(14, 118, 110, .09);
  pointer-events: none;
}

.eyebrow {
  margin: 0 0 1rem;
  color: var(--accent);
  font-size: .76rem;
  font-weight: 800;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.hero h1 {
  position: relative;
  z-index: 1;
  max-width: 820px;
  margin: 0;
  font: 700 clamp(3rem, 7.5vw, 6.5rem)/.95 Georgia, "Times New Roman", serif;
  letter-spacing: -.055em;
}

.hero h1 em { color: var(--accent); font-weight: 400; }

.lead {
  max-width: 650px;
  margin: 2rem 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.28rem);
}

.organizers {
  display: flex;
  align-items: flex-start;
  gap: .8rem;
  margin-top: 2.25rem;
}

.organizers img { margin-top: .2rem; }
.organizers p { margin: 0; }

.notice {
  display: flex;
  gap: 1rem;
  margin: 2.5rem 0 5rem;
  padding: 1.25rem 1.4rem;
  border: 1px solid #cfe1dc;
  border-radius: 14px;
  background: var(--accent-soft);
}

.notice img { flex: 0 0 auto; margin-top: .15rem; }
.notice p { margin: 0; color: #34514f; }

.section-heading { margin-bottom: 2rem; }
.section-heading h2 {
  margin: 0;
  font: 700 clamp(2.2rem, 5vw, 4rem)/1 Georgia, "Times New Roman", serif;
  letter-spacing: -.04em;
}

/* Chaque conférence est simplement composée d'un h1 suivi d'un dl. */
.seminars > h1 {
  margin: 1.2rem 0 0;
  padding: 2rem 2rem .55rem;
  border: 1px solid var(--line);
  border-bottom: 0;
  border-radius: var(--radius) var(--radius) 0 0;
  background: var(--card);
  box-shadow: var(--shadow);
  font: 650 clamp(1.32rem, 2.5vw, 1.75rem)/1.28 Georgia, "Times New Roman", serif;
  letter-spacing: -.018em;
}

.seminars > h1 a { color: var(--ink); text-decoration: none; }

.seminars > dl {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  margin: 0 0 1.5rem;
  padding: .8rem 2rem 2rem;
  border: 1px solid var(--line);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
  background: var(--card);
  box-shadow: var(--shadow);
}

.seminars dt {
  padding: .55rem 1rem .55rem 0;
  color: var(--muted);
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .09em;
  text-transform: uppercase;
}

.seminars dd {
  min-width: 0;
  margin: 0;
  padding: .45rem 0;
}

.seminars dd i { color: #3f4d51; font-style: normal; }
.seminars > br { display: none; }
.seminars strike { color: var(--muted); }

mjx-container[display="true"] {
  overflow-x: auto;
  overflow-y: hidden;
  padding-block: .4rem;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  margin-top: 5rem;
  padding: 2rem 0 3rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .9rem;
}

footer p { margin: 0; }

@media (max-width: 720px) {
  .header-inner { min-height: 70px; gap: .7rem; }
  .brand { gap: .45rem; }
  .brand img { width: 34px; height: 34px; }
  .brand span { display: none; }
  .header-logos { flex: 1; justify-content: flex-end; gap: .55rem; }
  .header-logos .header-logo-lis { width: 44px !important; height: 36px !important; }
  .header-logos .header-logo-univ { width: 82px !important; height: 24px !important; }
  .header-logos .header-logo-geii { width: 68px !important; height: 28px !important; }
  .hero::after { opacity: .35; }
  .seminars > h1 { padding: 1.4rem 1.25rem .45rem; }
  .seminars > dl { grid-template-columns: 1fr; padding: .6rem 1.25rem 1.4rem; }
  .seminars dt { padding: .8rem 0 0; }
  .seminars dd { padding-top: .1rem; }
  footer { flex-direction: column; gap: .5rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}