/* ── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #1a1a2e;
  background: #fff;
}
a { color: #1a6ea8; text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Nav ──────────────────────────────────────────────────── */
nav {
  position: sticky; top: 0; z-index: 100;
  background: #1c3f6e;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 2rem;
  height: 56px;
  box-shadow: 0 2px 8px rgba(0,0,0,.25);
}
.nav-brand {
  color: #fff; font-weight: 700; font-size: 1rem;
  letter-spacing: .02em; white-space: nowrap;
}
.nav-links { display: flex; gap: 0; }
.nav-links a {
  color: rgba(255,255,255,.82);
  font-size: .875rem;
  padding: .9rem 1.1rem;
  display: block;
  border-bottom: 3px solid transparent;
  transition: color .15s, border-color .15s;
}
.nav-links a:hover, .nav-links a.active {
  color: #fff; border-bottom-color: #2aafb0;
  text-decoration: none;
}

/* ── Hero ─────────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, #1c3f6e 0%, #0f2440 100%);
  color: #fff;
  padding: 4rem 2rem 3.5rem;
  text-align: center;
}
.hero .tag {
  display: inline-block;
  background: rgba(42,175,176,.22);
  border: 1px solid rgba(42,175,176,.5);
  color: #7de0e1;
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: .3rem .9rem;
  border-radius: 2rem;
  margin-bottom: 1.25rem;
}
.hero h1 {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
  max-width: 760px; margin: 0 auto .75rem;
}
.hero .acronym {
  color: #2aafb0; font-size: 1.1rem; font-weight: 600;
  margin-bottom: 1.25rem;
}
.hero .meta {
  font-size: .95rem; color: rgba(255,255,255,.72);
  display: flex; gap: 1.5rem; justify-content: center; flex-wrap: wrap;
}
.hero .meta span::before { content: "📍 "; }
.hero .meta span:nth-child(2)::before { content: "📅 "; }
.hero .meta span:nth-child(3)::before { content: "🔀 "; }

/* ── Dates Banner ─────────────────────────────────────────── */
.dates-banner {
  background: #f0f7ff;
  border-top: 3px solid #2aafb0;
  padding: 1rem 2rem;
  display: flex; gap: 2rem; justify-content: center; flex-wrap: wrap;
}
.dates-banner .date-item { text-align: center; }
.dates-banner .date-label {
  font-size: .72rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .08em; color: #6b7280;
}
.dates-banner .date-val {
  font-size: .95rem; font-weight: 600; color: #1c3f6e;
}

/* ── Container & Sections ─────────────────────────────────── */
.container { max-width: 900px; margin: 0 auto; padding: 0 2rem; }
section { padding: 3rem 0; }
section:nth-child(even) { background: #f7f9fc; }
h2 {
  font-size: 1.35rem; font-weight: 700; color: #1c3f6e;
  margin-bottom: 1.25rem;
  padding-bottom: .5rem;
  border-bottom: 2px solid #2aafb0;
  display: inline-block;
}
h3 { font-size: 1.05rem; font-weight: 700; color: #1c3f6e; margin: 1.25rem 0 .5rem; }
p { margin-bottom: .9rem; color: #2d2d3e; }

/* ── Pillars ──────────────────────────────────────────────── */
.pillars {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem; margin-top: 1.5rem;
}
.pillar {
  background: #fff;
  border: 1px solid #dce8f5;
  border-top: 4px solid #2aafb0;
  border-radius: 6px;
  padding: 1.25rem 1.25rem 1.5rem;
}
.pillar .p-num {
  font-size: .7rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; color: #2aafb0; margin-bottom: .4rem;
}
.pillar h3 { margin: 0 0 .6rem; font-size: .95rem; }
.pillar p { font-size: .88rem; color: #4b5563; margin: 0; }

/* ── Lists ────────────────────────────────────────────────── */
ul { list-style: none; padding: 0; }
ul li {
  padding: .3rem 0 .3rem 1.3rem;
  position: relative; font-size: .95rem; color: #2d2d3e;
}
ul li::before {
  content: "›"; position: absolute; left: 0;
  color: #2aafb0; font-weight: 700; font-size: 1.1rem; line-height: 1.5;
}
ul.plain li::before { display: none; }
ul.plain li { padding-left: 0; }

/* ── Topic groups ─────────────────────────────────────────── */
.topic-group { margin-bottom: 1.5rem; }
.topic-group h3 {
  font-size: .85rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .08em; color: #2aafb0; margin-bottom: .5rem; margin-top: 0;
  border: none;
}

/* ── Submission boxes ─────────────────────────────────────── */
.sub-types { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1.25rem 0; }
.sub-box {
  border: 1px solid #dce8f5; border-radius: 6px; padding: 1rem 1.25rem;
  background: #fff;
}
.sub-box .sub-label {
  font-size: .75rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .08em; color: #2aafb0; margin-bottom: .35rem;
}
.sub-box p { font-size: .88rem; margin: 0; color: #4b5563; }

/* ── Organiser cards ──────────────────────────────────────── */
.org-grid { display: flex; flex-direction: column; gap: 1rem; margin-top: 1.25rem; }
.org-card {
  display: flex; gap: 1.25rem; align-items: flex-start;
  border: 1px solid #dce8f5; border-radius: 6px; padding: 1.1rem 1.25rem;
  background: #fff;
}
.org-avatar {
  width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(135deg, #1c3f6e, #2aafb0);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 700; font-size: 1.1rem; flex-shrink: 0;
}
.org-info h3 { margin: 0 0 .1rem; font-size: 1rem; }
.org-info .org-role { font-size: .82rem; color: #6b7280; margin-bottom: .4rem; }
.org-info p { font-size: .88rem; margin: 0; color: #4b5563; }
.org-info a { font-size: .82rem; }

/* ── PC table ─────────────────────────────────────────────── */
.pc-table { width: 100%; border-collapse: collapse; margin-top: 1rem; font-size: .9rem; }
.pc-table th {
  background: #1c3f6e; color: #fff; font-weight: 600;
  padding: .6rem 1rem; text-align: left; font-size: .82rem;
}
.pc-table td { padding: .55rem 1rem; border-bottom: 1px solid #e5eaf2; }
.pc-table tr:last-child td { border-bottom: none; }
.pc-table tr:nth-child(even) td { background: #f7f9fc; }

/* ── Footer ───────────────────────────────────────────────── */
footer {
  background: #0f2440; color: rgba(255,255,255,.6);
  text-align: center; padding: 1.5rem 2rem;
  font-size: .82rem; margin-top: 2rem;
}
footer a { color: rgba(255,255,255,.8); }

/* ── Agenda table ─────────────────────────────────────────── */
.agenda { width: 100%; border-collapse: collapse; margin-top: 1rem; font-size: .9rem; }
.agenda th {
  background: #1c3f6e; color: #fff; padding: .6rem 1rem;
  text-align: left; font-size: .82rem;
}
.agenda td { padding: .65rem 1rem; border-bottom: 1px solid #e5eaf2; vertical-align: top; }
.agenda td:first-child { white-space: nowrap; font-weight: 600; color: #1c3f6e; width: 110px; }
.agenda tr:nth-child(even) td { background: #f7f9fc; }
.agenda .session-detail { font-size: .82rem; color: #6b7280; margin-top: .2rem; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 640px) {
  .nav-links a { padding: .9rem .7rem; font-size: .8rem; }
  .sub-types { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.5rem; }
  .org-card { flex-direction: column; }
}