:root {
  --red: #C41230;
  --red-dark: #9c0e26;
  --ink: #1A1A1A;
  --ink-soft: #4a4a4a;
  --bg: #ffffff;
  --bg-alt: #FAFAFA;
  --bg-warm: #F5F4F2;
  --border: #e6e3e0;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --max-width: 1080px;
  --max-width-narrow: 720px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

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

a {
  color: var(--red);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 0.5em;
  color: var(--ink);
}

h1 { font-size: clamp(2rem, 4.5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: 1.15rem; }

p { margin: 0 0 1em; color: var(--ink-soft); }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.container.narrow { max-width: var(--max-width-narrow); }
.container.schedule-wrap { max-width: 880px; }

/* Header / nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.wordmark {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink);
}
.wordmark:hover { text-decoration: none; color: var(--red); }

.wordmark-logo {
  width: 32px;
  height: 32px;
  display: block;
}

.site-nav {
  display: flex;
  gap: 28px;
}
.site-nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--ink-soft);
  white-space: nowrap;
}
.site-nav a:hover {
  color: var(--red);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}
.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--ink);
}

/* Hero */
.hero {
  padding: 96px 0 0;
  background: var(--bg-warm);
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.hero-title {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  max-width: 880px;
  margin: 0 auto;
}

.hero-logo {
  width: 160px;
  height: 160px;
  flex-shrink: 0;
}

.hero h1 { max-width: 820px; margin: 0; }

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--ink);
  font-weight: 500;
  margin-top: 1.2em;
}

.hero-meta {
  font-size: 1rem;
  color: var(--ink-soft);
}

.countdown {
  margin-top: 1.5em;
  font-family: var(--sans);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--red-dark);
}

.hero-sponsors {
  margin-top: 2.4em;
  padding: 1.8em 0;
  border-top: 1px solid var(--border);
}

.hero-sponsors-logos {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  flex-wrap: wrap;
  gap: 72px;
  max-width: 880px;
  margin: 0 auto;
}

.sponsor-logo img {
  margin-top: 2px;
}

.sponsor-logo {
  display: flex;
  align-items: center;
  gap: 16px;
  opacity: 0.85;
  transition: opacity 0.15s ease;
}
.sponsor-logo:hover {
  opacity: 1;
  text-decoration: none;
}
.sponsor-logo img {
  display: block;
}
.sponsor-logo-mcwilliams span {
  font-family: var(--sans);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink);
  text-align: left;
  max-width: 200px;
  line-height: 1.3;
}

/* Sections */
.section {
  padding: 72px 0;
}
.section.alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 0.6em;
}

.tbd-note {
  font-style: italic;
  color: var(--ink-soft);
}

.button {
  display: inline-block;
  margin-top: 8px;
  padding: 12px 28px;
  background: var(--red);
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: 4px;
  text-decoration: none;
}
.button:hover {
  background: var(--red-dark);
  text-decoration: none;
}

.registration-contact {
  margin-top: 20px;
  font-size: 0.9rem;
}

.topic-list {
  margin: 28px 0 28px;
  padding: 0;
  list-style: none;
}
.topic-list li {
  position: relative;
  padding-left: 22px;
  color: var(--ink-soft);
}
.topic-list li + li {
  margin-top: 14px;
}
.topic-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--red);
}
.topic-list strong {
  color: var(--ink);
}

.address-block {
  margin: 20px 0;
  padding: 20px 24px;
  background: var(--bg-alt);
  border-left: 3px solid var(--red);
  font-size: 0.95rem;
  line-height: 1.7;
}

.directions-list {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: directions;
}
.directions-list li {
  position: relative;
  padding-left: 34px;
  color: var(--ink-soft);
  counter-increment: directions;
}
.directions-list li + li {
  margin-top: 14px;
}
.directions-list li::before {
  content: counter(directions);
  position: absolute;
  left: 0;
  top: 0;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--red);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Cards */
.card-grid {
  display: grid;
  gap: 24px;
  margin-top: 32px;
}
.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 28px;
}
.section.alt .card { background: var(--bg); }

/* Timeline (format section) */
.timeline {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 32px;
}
.timeline-block {
  border-left: 3px solid var(--red);
  padding-left: 24px;
}
.timeline-dates {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--red-dark);
  letter-spacing: 0.02em;
  margin-bottom: 0.4em;
}

/* Schedule table */
.schedule-details {
  margin-top: 8px;
}
.schedule-details summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--red);
  list-style: none;
}
.schedule-details summary::-webkit-details-marker {
  display: none;
}
.schedule-details summary::before {
  content: "\25B8";
  display: inline-block;
  transition: transform 0.15s ease;
}
.schedule-details[open] summary::before {
  transform: rotate(90deg);
}
.schedule-details summary:hover {
  color: var(--red-dark);
}
.schedule-day-block {
  margin-top: 40px;
}
.schedule-day-block:first-child {
  margin-top: 32px;
}
.schedule-day-block h3 {
  margin-bottom: 0.8em;
}
.schedule-table-wrap {
  overflow-x: auto;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
}
.schedule-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}
.schedule-table td {
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
.schedule-table tr:last-child td {
  border-bottom: none;
}
.schedule-table .time {
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
  width: 1%;
}
.schedule-table .session {
  font-weight: 500;
  white-space: normal;
  width: 100%;
}
.schedule-table .session.invited {
  color: var(--red-dark);
}
.schedule-table .session.opening {
  color: var(--red-dark);
}
.schedule-table .session.contributed {
  color: var(--ink-soft);
}
.schedule-table .session.discussion {
  color: var(--ink-soft);
}
.schedule-table .session.hackathon {
  color: var(--ink-soft);
  font-style: italic;
}
.schedule-table .session-type {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.schedule-table .session-title {
  display: block;
  margin-top: 3px;
  font-size: 0.98rem;
  font-weight: 600;
  font-style: normal;
  color: var(--ink);
}
.abstract-toggle {
  display: block;
}
.abstract-toggle summary {
  cursor: pointer;
  list-style: none;
}
.abstract-toggle summary::-webkit-details-marker {
  display: none;
}
.abstract-toggle summary::after {
  content: "Show abstract";
  display: inline-block;
  margin-left: 8px;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--red);
  vertical-align: middle;
}
.abstract-toggle[open] summary::after {
  content: "Hide abstract";
}
.abstract-toggle summary:hover::after {
  color: var(--red-dark);
}
.session-abstract {
  margin-top: 8px;
  max-width: 640px;
}
.session-abstract p {
  font-size: 0.88rem;
  color: var(--ink-soft);
  font-weight: 400;
  margin: 0 0 0.8em;
}
.session-abstract p:last-child {
  margin-bottom: 0;
}
.schedule-table .speaker {
  color: var(--ink-soft);
  font-style: italic;
  white-space: nowrap;
  width: 1%;
}
.schedule-table .speaker.known {
  color: var(--ink);
  font-style: normal;
  font-weight: 500;
}
.schedule-table .break-row {
  background: var(--bg-alt);
}
.schedule-table .session.break {
  color: var(--ink-soft);
  font-style: italic;
  font-weight: 400;
}
.schedule-table .session.dinner {
  color: var(--ink);
  font-style: normal;
  font-weight: 600;
}

/* Speakers */
.speaker-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 24px;
}
.speaker-card {
  flex: 0 1 328px;
  padding: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-width: 0;
}
.speaker-photo-wrap {
  aspect-ratio: 1 / 1;
  background: var(--bg-alt);
}
.speaker-photo-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.speaker-info {
  padding: 18px 22px 22px;
}
.speaker-name {
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.2em;
}
.speaker-role {
  font-size: 0.9rem;
  color: var(--ink-soft);
  margin-bottom: 0;
}
/* Hackathon tracks */
.track-grid {
  grid-template-columns: 1fr;
}
.track-card h3 {
  color: var(--red-dark);
  font-size: 1.05rem;
}
.track-card p {
  margin-bottom: 0;
}
.track-winners {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}
.track-winners-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
  margin-bottom: 0.6em;
}
.track-winner {
  font-size: 0.92rem;
  color: var(--ink);
  margin-bottom: 0.4em;
}
.track-winner:last-child {
  margin-bottom: 0;
}
.track-winner .place {
  font-weight: 600;
  color: var(--red-dark);
  margin-right: 6px;
}

/* Committee */
.committee-grid {
  grid-template-columns: repeat(2, 1fr);
}
.committee-name {
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.2em;
}
.committee-name a {
  color: var(--ink);
  text-decoration: none;
}
.committee-name a:hover {
  color: var(--red);
  text-decoration: underline;
}
.committee-affiliation {
  font-size: 0.9rem;
  color: var(--ink-soft);
  margin-bottom: 0;
}

/* Footer */
.site-footer {
  background: var(--ink);
  color: #cfcfcf;
  padding: 48px 0;
  text-align: center;
}
.footer-logo {
  width: 56px;
  height: 56px;
  display: block;
  margin: 0 auto 20px;
  border-radius: 50%;
}
.site-footer p {
  color: #b8b8b8;
  font-size: 0.9rem;
  margin: 0 0 0.5em;
}
.footer-title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.05rem;
  color: #fff;
}
.site-footer a {
  color: #e9a6b2;
}
.footer-fine {
  margin-top: 1.5em;
  font-size: 0.8rem;
  color: #888;
}
/* Responsive */
@media (max-width: 760px) {
  .site-nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 12px 24px 20px;
    gap: 4px;
    display: none;
  }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 10px 0; }
  .nav-toggle { display: flex; }

  .timeline,
  .committee-grid {
    grid-template-columns: 1fr;
  }
  .speaker-card {
    flex-basis: calc(50% - 12px);
  }
  .schedule-table, .schedule-table tbody, .schedule-table tr {
    display: block;
    width: 100%;
  }
  .schedule-table tr {
    padding: 12px 20px;
    border-bottom: 1px solid var(--border);
  }
  .schedule-table tr:last-child {
    border-bottom: none;
  }
  .schedule-table td {
    display: block;
    width: auto;
    padding: 0;
    border-bottom: none;
    white-space: normal;
  }
  .schedule-table .time {
    width: auto;
    margin-bottom: 4px;
  }
  .schedule-table .speaker {
    width: auto;
    margin-top: 6px;
    font-size: 0.85rem;
    white-space: normal;
  }
  .schedule-table .break-row {
    padding: 8px 20px;
  }
  .hero { padding: 72px 0 0; }
  .section { padding: 56px 0; }

  .hero-title {
    flex-direction: column;
    gap: 16px;
  }
  .hero-logo {
    width: 110px;
    height: 110px;
  }
}