:root {
  --navy: #0b0469;
  --navy-2: #140c8a;
  --accent: #2920be;
  --sky: #6a8afc;
  --lav: #f4f2ff;
  --ink: #11101a;
  --muted: #55526b;
  --line: #d9d6ee;
  --white: #ffffff;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans: "Instrument Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --radius: 16px;
  --max: 1160px;
  --nav-h: 72px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); }
h1, h2, h3, h4 { font-family: var(--serif); font-weight: 500; line-height: 1.1; margin: 0; letter-spacing: -0.01em; }

.container { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 20px; border-radius: 999px;
  font: 500 15px/1.2 var(--sans); text-decoration: none; white-space: nowrap;
  border: 1px solid transparent; transition: background .2s, color .2s, border-color .2s;
}
.btn-light { background: var(--lav); color: var(--navy); }
.btn-light:hover { background: var(--white); }
.btn-outline-light { color: var(--lav); border-color: rgba(244, 242, 255, .5); }
.btn-outline-light:hover { border-color: var(--lav); background: rgba(244, 242, 255, .08); }
.btn-dark { background: var(--navy); color: var(--lav); }
.btn-dark:hover { background: var(--accent); }

/* Nav */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  color: var(--lav); transition: background .25s, box-shadow .25s;
}
.nav.scrolled, .nav.open { background: var(--navy); box-shadow: 0 1px 0 rgba(255, 255, 255, .08); }
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.brand {
  color: var(--lav); text-decoration: none; font-family: var(--serif); font-size: 19px; font-weight: 500;
  line-height: 1.2;
}
.hero-presenter { display: flex; align-items: flex-end; gap: 14px; margin-bottom: 28px; }
.hero-logo-link { display: block; }
.presents {
  font-family: var(--serif); font-size: 26px; line-height: 1;
  color: var(--lav); opacity: .85; padding-bottom: 2px;
}
.hero-logo-link:hover { opacity: .8; }
.hero-logo { height: 44px; width: auto; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a:not(.btn) { color: var(--lav); text-decoration: none; font-size: 15px; opacity: .85; }
.nav-links a:not(.btn):hover { opacity: 1; text-decoration: underline; text-underline-offset: 4px; }
.nav-toggle { display: none; background: none; border: 0; color: inherit; padding: 4px; cursor: pointer; }

/* Hero */
.hero {
  position: relative; overflow: hidden;
  background: var(--navy); color: var(--lav);
  display: flex; align-items: center;
  padding: calc(var(--nav-h) + 64px) 0 72px;
}
.hero-lines {
  position: absolute; right: -4%; top: var(--nav-h); height: calc(100% - var(--nav-h)); width: 60%;
  color: var(--sky); opacity: .45;
}
.hero-content { position: relative; width: 100%; }
.hero h1 { font-size: clamp(30px, 4.4vw, 52px); max-width: 20ch; }
.hero-sub { font-size: clamp(18px, 2vw, 21px); max-width: 38ch; margin: 24px 0 0; opacity: .9; }
.hero-date {
  margin: 32px 0 0; font-size: 15px; font-weight: 600; letter-spacing: .14em; text-transform: uppercase;
  display: inline-block; padding: 8px 16px; border: 1px solid rgba(244, 242, 255, .35); border-radius: 999px;
}

/* Sections */
.section { padding: 96px 0; }
.section-tint { background: var(--lav); }
.section-head {
  display: grid; grid-template-columns: 1fr 1fr; gap: 32px; align-items: start;
  margin-bottom: 48px;
}
.section-head h2 { font-size: clamp(34px, 4.4vw, 52px); }
.section-head p { margin: 6px 0 0; color: var(--muted); font-size: 17px; }

/* About */
.about-body { max-width: 760px; margin-left: auto; margin-right: 0; }
.about-body p { margin: 0 0 18px; font-size: 17px; color: #2b2940; }
.about-body .lead { font-family: var(--serif); font-size: 26px; line-height: 1.35; color: var(--navy); margin-bottom: 28px; }
.formats {
  list-style: none; padding: 0; margin: 56px 0 0;
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px;
}
.formats li {
  border: 1px solid var(--ink); border-radius: var(--radius);
  padding: 18px; font-weight: 500; display: flex; flex-direction: column; gap: 22px; min-height: 120px;
}
.formats .num { font-family: var(--serif); color: var(--accent); font-size: 22px; }

/* Apply band */
.apply-band { background: var(--lav); color: var(--navy); padding: 56px 0; }
.apply-inner { display: flex; flex-direction: column; align-items: center; gap: 20px; text-align: center; }
.btn-apply {
  background: var(--navy); color: var(--lav);
  font-size: 20px; font-weight: 600; padding: 18px 44px;
  box-shadow: 0 10px 30px rgba(11, 4, 105, .25);
}
.btn-apply:hover { background: var(--accent); transform: translateY(-1px); }

/* Schedule */
.tba {
  border: 1px dashed var(--accent); border-radius: var(--radius); background: var(--white);
  padding: 48px 32px; text-align: center;
}
.tba-label { font-family: var(--serif); font-size: 32px; color: var(--navy); margin: 0 0 8px; }
.tba p:last-child { margin: 0; color: var(--muted); }

/* Research */
.research-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.research-card {
  display: flex; flex-direction: column; gap: 12px;
  border: 1px solid var(--ink); border-radius: var(--radius); padding: 26px;
  background: var(--white); color: var(--ink); text-decoration: none;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.research-card.is-link:hover { transform: translateY(-2px); border-color: var(--accent); box-shadow: 0 10px 30px rgba(11, 4, 105, .1); }
.research-card h3 { font-size: 24px; color: var(--navy); }
.people { margin: 0; font-size: 14px; }
.people span { color: var(--muted); text-transform: uppercase; letter-spacing: .08em; font-size: 11px; font-weight: 600; margin-right: 2px; }
.people .sep { margin: 0 6px; letter-spacing: 0; }
.summary { margin: 0; color: #3a3850; font-size: 15px; flex: 1; }
.card-foot { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 6px; }
.tags { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.tags li { font-size: 12px; font-weight: 500; padding: 4px 10px; border-radius: 999px; background: var(--lav); color: var(--accent); }
.more { font-size: 14px; color: var(--accent); font-weight: 500; white-space: nowrap; }

/* Speakers */
.speaker-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 24px; }
.speaker {
  background: none; border: 0; padding: 0; text-align: left; cursor: pointer; font: inherit; color: inherit;
  display: flex; flex-direction: column;
}
.speaker-photo {
  width: 100%; aspect-ratio: 1; object-fit: cover; border-radius: var(--radius);
  transition: transform .25s, box-shadow .25s;
}
.speaker:hover .speaker-photo, .speaker:focus-visible .speaker-photo { transform: translateY(-3px); box-shadow: 0 12px 30px rgba(11, 4, 105, .18); }
.initials {
  display: grid; place-items: center; background: var(--navy); color: var(--lav);
  font-family: var(--serif); font-size: 48px;
  background-image: radial-gradient(circle at 80% 20%, rgba(106, 138, 252, .45), transparent 60%);
}
.speaker-name { margin-top: 14px; font-family: var(--serif); font-size: 21px; color: var(--navy); }
.speaker-org { font-size: 14px; color: var(--muted); }

.speaker-modal {
  border: 0; border-radius: 20px; padding: 0; width: min(640px, calc(100vw - 32px));
  max-height: calc(100vh - 48px); color: var(--ink);
}
.speaker-modal::backdrop { background: rgba(11, 4, 105, .55); backdrop-filter: blur(3px); }
.modal-body { padding: 36px; }
.modal-close {
  position: absolute; top: 12px; right: 14px; border: 0; background: none; font-size: 30px; line-height: 1;
  color: var(--muted); cursor: pointer; padding: 4px 8px;
}
.modal-close:hover { color: var(--ink); }
.modal-top { display: flex; gap: 20px; align-items: center; margin-bottom: 22px; padding-right: 24px; }
.modal-photo { width: 104px; height: 104px; flex: none; border-radius: 14px; object-fit: cover; }
.modal-photo.initials { font-size: 34px; }
.modal-top h3 { font-size: 30px; color: var(--navy); }
.modal-role { margin: 4px 0 0; color: var(--muted); }
.modal-links { margin: 10px 0 0; display: flex; flex-wrap: wrap; gap: 14px; font-size: 14px; font-weight: 500; }
.modal-bio { margin: 0 0 24px; }
.modal-talk { background: var(--lav); border-radius: 14px; padding: 20px 22px; }
.modal-talk .label { margin: 0 0 6px; text-transform: uppercase; letter-spacing: .12em; font-size: 12px; font-weight: 600; color: var(--accent); }
.modal-talk h4 { font-size: 22px; color: var(--navy); margin-bottom: 8px; }
.modal-talk p:last-child { margin: 0; }

/* Venue */
.venue { display: grid; grid-template-columns: 5fr 7fr; gap: 40px; align-items: stretch; }
.venue-info h3 { font-size: 32px; color: var(--navy); margin-bottom: 14px; }
.venue-info .address { font-weight: 500; font-size: 17px; }
.venue-info p { margin: 0 0 18px; }
.venue-info .btn { margin-top: 8px; }
.map { border-radius: var(--radius); overflow: hidden; border: 1px solid var(--ink); min-height: 360px; }
.map iframe { width: 100%; height: 100%; min-height: 360px; border: 0; display: block; }

/* FAQ */
.faq { max-width: 860px; margin-left: auto; }
.faq details { border-bottom: 1px solid #cfcaf0; }
.faq details:first-child { border-top: 1px solid #cfcaf0; }
.faq summary {
  list-style: none; cursor: pointer; padding: 22px 40px 22px 0; position: relative;
  font-family: var(--serif); font-size: 22px; color: var(--navy);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; position: absolute; right: 4px; top: 50%; transform: translateY(-50%);
  font-family: var(--sans); font-size: 26px; color: var(--accent); transition: transform .2s;
}
.faq details[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq details p { margin: 0 0 22px; color: #3a3850; max-width: 70ch; }

/* CTA band + footer */
.footer { background: var(--navy); color: rgba(244, 242, 255, .8); padding: 48px 0; font-size: 14px; }
.footer-inner { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer p { margin: 0; }
.footer-title { font-family: var(--serif); font-size: 20px; color: var(--lav); margin-bottom: 6px !important; }
.footer-links { display: flex; gap: 20px; align-items: center; flex-wrap: wrap; }
.footer-links a { color: var(--lav); text-decoration: none; }
.footer-links a:hover { text-decoration: underline; }

/* Responsive */
@media (max-width: 1020px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 4px;
    background: var(--navy); padding: 8px 24px 24px;
  }
  .nav.open .nav-links { display: flex; }
  .nav-links a:not(.btn) { padding: 8px 0; font-size: 17px; }
  .nav-links .btn { margin-top: 10px; }
  .formats { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 760px) {
  .container, .nav-inner { padding-left: 16px; padding-right: 16px; }
  .brand { font-size: 17px; }
  .hero-logo { height: 34px; }
  .presents { font-size: 21px; }
  .section { padding: 64px 0; }
  .section-head { grid-template-columns: 1fr; gap: 12px; margin-bottom: 32px; }
  .hero { padding: calc(var(--nav-h) + 40px) 0 56px; }
  .hero-lines { width: 100%; opacity: .2; }
  .about-body .lead { font-size: 22px; }
  .formats { grid-template-columns: repeat(2, 1fr); }
  .formats li { min-height: 96px; }
  .research-grid { grid-template-columns: 1fr; }
  .speaker-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .venue { grid-template-columns: 1fr; }
  .modal-body { padding: 28px 22px; }
  .modal-top { flex-direction: column; align-items: flex-start; }
  .faq summary { font-size: 19px; }
}