:root {
  --text: #1f2933;
  --muted: #5f6b76;
  --line: #d9dee5;
  --soft: #f6f8fa;
  --accent: #1f5f7a;
  --white: #ffffff;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--white);
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.6;
}

a {
  color: var(--accent);
  text-underline-offset: 0.18em;
}

.page-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.top-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
  padding: 14px 0;
  font-family: Arial, Helvetica, sans-serif;
}

.site-name {
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

.top-nav div {
  display: flex;
  gap: 18px;
}

.top-nav a:not(.site-name) {
  color: var(--muted);
  font-size: 0.95rem;
  text-decoration: none;
}

.section {
  scroll-margin-top: 72px;
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.hero {
  padding-top: 64px;
}

h1,
h2,
h3 {
  margin: 0;
  color: var(--text);
  line-height: 1.2;
}

h1 {
  max-width: 900px;
  font-size: clamp(2.4rem, 6vw, 4.8rem);
  font-weight: 700;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(1.8rem, 3vw, 2.45rem);
}

h3 {
  font-size: 1.45rem;
}

.event-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 30px 0 0;
}

.event-meta div {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--soft);
}

.event-meta dt {
  margin-bottom: 6px;
  color: var(--muted);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.event-meta dd {
  margin: 0;
  font-weight: 700;
}

.prose {
  max-width: 920px;
}

.prose p {
  margin: 0 0 16px;
  color: var(--text);
  font-size: 1.06rem;
}

.speaker-list {
  display: grid;
  gap: 22px;
}

.timetable {
  overflow: hidden;
  margin: 0 0 28px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--white);
}

.timetable-row {
  display: grid;
  grid-template-columns: 140px minmax(210px, 0.7fr) minmax(0, 1.3fr);
}

.timetable-row > div {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
}

.timetable-row:last-child > div {
  border-bottom: 0;
}

.timetable-head {
  color: var(--white);
  background: var(--accent);
  font-family: Arial, Helvetica, sans-serif;
  font-weight: 700;
}

.timetable-break {
  background: var(--soft);
}

.speaker-card {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--white);
}

.speaker-card figure {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 260px;
  margin: 0;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--soft);
}

.speaker-card img {
  width: 100%;
  max-height: 340px;
  object-fit: contain;
}

.affiliation {
  margin: 6px 0 14px;
  color: var(--muted);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 0.98rem;
  font-weight: 700;
}

.speaker-card p {
  margin: 0 0 12px;
}

.talk {
  color: var(--text);
}

.organizer-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.organizer-grid article {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--soft);
}

.organizer-grid h3 {
  font-size: 1.3rem;
}

.organizer-grid p {
  margin: 8px 0;
  color: var(--muted);
}

.footer {
  width: min(1120px, calc(100% - 36px));
  margin: 0 auto;
  padding: 28px 0 40px;
  color: var(--muted);
  font-family: Arial, Helvetica, sans-serif;
}

@media (max-width: 820px) {
  .top-nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .top-nav div {
    flex-wrap: wrap;
  }

  .event-meta,
  .organizer-grid,
  .speaker-card,
  .timetable-row {
    grid-template-columns: 1fr;
  }

  .timetable-head {
    display: none;
  }

  .timetable-row > div {
    padding: 8px 12px;
    border-bottom: 0;
  }

  .timetable-row > div:first-child {
    padding-top: 12px;
    color: var(--muted);
    font-family: Arial, Helvetica, sans-serif;
    font-size: 0.85rem;
    font-weight: 700;
  }

  .timetable-row > div:last-child {
    padding-bottom: 12px;
    border-bottom: 1px solid var(--line);
  }

  .speaker-card figure {
    min-height: 0;
  }

  .speaker-card img {
    max-height: 420px;
  }
}