:root {
  --bg: #f7f8fb;
  --text: #1f2937;
  --muted: #5b6472;
  --primary: #1f5f8b;
  --primary-dark: #143c5a;
  --accent: #e9f4ff;
  --card: #ffffff;
  --border: #dfe6ef;
  --shadow: 0 10px 30px rgba(18, 43, 68, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}

.wrap {
  width: min(1080px, calc(100% - 40px));
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.nav-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 68px;
  gap: 24px;
}

.site-name {
  font-weight: 800;
  color: var(--primary-dark);
  text-decoration: none;
  font-size: 20px;
  letter-spacing: 0.02em;
}

nav {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 700;
  font-size: 15px;
}

nav a:hover,
nav a.active {
  color: var(--primary);
}

.hero {
  min-height: 520px;
  display: flex;
  align-items: center;
  background:
    linear-gradient(120deg, rgba(20, 60, 90, 0.92), rgba(31, 95, 139, 0.82)),
    url("assets/banner.svg") center/cover no-repeat;
  color: white;
}

.hero-inner {
  padding: 80px 0;
}

.eyebrow {
  margin: 0 0 14px;
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-weight: 800;
  color: #d8ecff;
}

.hero h1,
.page-title h1 {
  margin: 0;
  max-width: 900px;
  font-size: clamp(38px, 6vw, 70px);
  line-height: 1.05;
  letter-spacing: -0.04em;
}

.hero-subtitle {
  max-width: 760px;
  font-size: 21px;
  margin: 24px 0 32px;
  color: rgba(255, 255, 255, 0.9);
}

.hero-summary {
  max-width: 760px;
  margin: 24px 0 28px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 20px;
}

.hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0 0 32px;
  padding: 0;
  list-style: none;
}

.hero-facts li {
  min-width: 180px;
  padding: 12px 16px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.12);
}

.hero-facts strong,
.hero-facts span {
  display: block;
}

.hero-facts strong {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #d8ecff;
}

.hero-facts span {
  margin-top: 4px;
  color: #ffffff;
  font-weight: 800;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 20px;
  border-radius: 999px;
  background: var(--primary);
  color: white;
  text-decoration: none;
  font-weight: 800;
  border: 2px solid var(--primary);
  box-shadow: 0 8px 20px rgba(18, 43, 68, 0.18);
}

.button:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
}

.button.ghost {
  background: rgba(255, 255, 255, 0.14);
  color: white;
  border-color: rgba(255, 255, 255, 0.65);
}

.button.small {
  padding: 10px 16px;
  font-size: 14px;
}

.page-title {
  padding: 86px 0;
  color: white;
  background: linear-gradient(120deg, var(--primary-dark), var(--primary));
}

main > .wrap,
main > .content-grid {
  margin-top: 30px;
  margin-bottom: 30px;
}

.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(280px, 0.9fr);
  gap: 24px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: 30px;
  box-shadow: var(--shadow);
}

.card + .card {
  margin-top: 24px;
}

.card.wide {
  min-height: 100%;
}

.card.highlight {
  background: linear-gradient(180deg, #ffffff, var(--accent));
}

.organization-band {
  margin: 18px 0 24px;
  padding: 34px 0 38px;
  background: #ffffff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.organization-band h2 {
  margin-bottom: 10px;
}

.sponsor-row {
  display: grid;
  grid-template-columns: repeat(5, minmax(150px, 1fr));
  gap: 28px;
  align-items: center;
  max-width: 1080px;
  margin: 0 auto;
}

.sponsor-logo {
  display: flex;
  min-height: 164px;
  align-items: center;
  justify-content: center;
  padding: 0 8px;
}

.sponsor-logo img {
  width: auto;
  max-width: 252px;
  max-height: 154px;
  object-fit: contain;
}

.sponsor-logo .logo-yili {
  max-width: 216px;
  max-height: 144px;
}

.sponsor-logo .logo-sjtu {
  max-width: 264px;
  max-height: 154px;
}

.sponsor-logo .logo-hunan {
  max-width: 208px;
  max-height: 150px;
}

.sponsor-logo .logo-wuhan {
  max-width: 218px;
  max-height: 152px;
}

.sponsor-logo .logo-westlake {
  max-width: 450px;
  max-height: 280px;
}

h2 {
  margin: 0 0 16px;
  color: var(--primary-dark);
  font-size: 28px;
  line-height: 1.2;
}

p {
  margin: 0 0 14px;
}

ul {
  margin: 0;
  padding-left: 22px;
}

li {
  margin: 8px 0;
}

.clean-list {
  list-style: none;
  padding-left: 0;
}

.date-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.date-item {
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--accent);
}

.date-item span {
  display: block;
  color: var(--muted);
  font-weight: 700;
  margin-bottom: 8px;
}

.date-item strong {
  color: var(--primary-dark);
  font-size: 22px;
}

table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border-radius: 12px;
}

.table-scroll {
  width: 100%;
  overflow-x: auto;
}

.schedule-table {
  min-width: 940px;
}

.schedule-table th:first-child,
.schedule-table td:first-child {
  width: 140px;
  white-space: nowrap;
  font-weight: 800;
  color: var(--primary-dark);
}

.schedule-table th:nth-child(2),
.schedule-table td:nth-child(2) {
  width: 150px;
  font-weight: 800;
}

.schedule-table th:nth-child(3),
.schedule-table td:nth-child(3) {
  width: 260px;
}

.schedule-speaker-name {
  font-weight: 800;
  color: var(--primary-dark);
}

.schedule-speaker-affiliation {
  display: inline-block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.35;
}

.schedule-special td {
  background: #f8fbff;
}

.schedule-break td {
  background: #fff7e8;
}

.schedule-poster td {
  background: #eef8f1;
}

th,
td {
  border: 1px solid var(--border);
  padding: 14px;
  text-align: left;
}

th {
  background: var(--accent);
  color: var(--primary-dark);
}

.organizers-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.organizer-card {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  background: white;
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: 24px;
  box-shadow: var(--shadow);
}

.organizer-card img {
  width: 118px;
  height: 118px;
  border-radius: 18px;
  object-fit: cover;
  flex: 0 0 auto;
  background: var(--accent);
}

.organizer-card h2 {
  font-size: 22px;
  margin-bottom: 6px;
}

.affiliation {
  color: var(--primary);
  font-weight: 800;
  margin-bottom: 10px;
}

a {
  color: var(--primary);
}

footer {
  margin-top: 60px;
  padding: 28px 0;
  color: white;
  background: var(--primary-dark);
  text-align: center;
}

footer p {
  margin: 0;
}

@media (max-width: 800px) {
  .nav-wrap {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
  }

  nav {
    justify-content: flex-start;
    gap: 12px;
  }

  .hero {
    min-height: 460px;
  }

  .organization-band {
    padding: 28px 0 32px;
  }

  .organization-band h2 {
    margin-bottom: 10px;
  }

  .content-grid,
  .organizers-grid,
  .date-grid {
    grid-template-columns: 1fr;
  }

  .sponsor-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .sponsor-logo {
    min-height: 124px;
  }

  .sponsor-logo img {
    max-width: 176px;
    max-height: 112px;
  }

  .sponsor-logo .logo-yili {
    max-width: 168px;
    max-height: 112px;
  }

  .sponsor-logo .logo-sjtu {
    max-width: 184px;
    max-height: 116px;
  }

  .sponsor-logo .logo-hunan {
    max-width: 158px;
    max-height: 112px;
  }

  .sponsor-logo .logo-wuhan {
    max-width: 168px;
    max-height: 114px;
  }

  .sponsor-logo .logo-westlake {
    max-width: 226px;
    max-height: 142px;
  }

  .organizer-card {
    flex-direction: column;
  }
}

.talk-card h3 {
  margin: 26px 0 8px;
  color: var(--primary-dark);
}

.talk-header {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 24px;
  align-items: center;
  margin-bottom: 24px;
}

.talk-photo {
  width: 150px;
  height: 150px;
  border-radius: 18px;
  object-fit: cover;
  border: 1px solid var(--border);
}

.section-label {
  margin: 0 0 8px;
  color: var(--primary);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 13px;
}

.speaker-name {
  margin: 12px 0 2px;
  font-weight: 800;
  color: var(--primary-dark);
}

.speaker-affiliation {
  margin: 0;
  color: var(--muted);
}

@media (max-width: 680px) {
  .talk-header {
    grid-template-columns: 1fr;
  }

  .talk-photo {
    width: 132px;
    height: 132px;
  }
}