:root {
  --ink: #20252b;
  --ink-soft: #46505a;
  --muted: #75808b;
  --blue: #2f557a;
  --blue-dark: #183b5c;
  --paper: #edf1f5;
  --paper-warm: #f5f5f2;
  --line: rgba(32, 37, 43, 0.16);
  --glass: rgba(255, 255, 255, 0.67);
  --shadow: 0 22px 65px rgba(23, 35, 47, 0.12);
  --serif: 'Playfair Display', 'Noto Serif SC', Georgia, serif;
  --sans: 'Noto Sans', 'Noto Sans SC', system-ui, sans-serif;
  --cn-serif: 'Noto Serif SC', serif;
  --header-height: 82px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-height) + 18px); }
body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: #d9dfe5;
  font-family: var(--sans);
  line-height: 1.6;
}
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; }
::selection { color: #fff; background: var(--blue-dark); }

.background {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    linear-gradient(180deg, rgba(238, 241, 245, 0.08) 0%, rgba(238, 241, 245, 0.45) 50%, rgba(223, 229, 235, 0.96) 100%),
    url('./skyline-bg.jpg') center bottom / cover no-repeat;
}
.background::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 78% 17%, rgba(255, 255, 255, 0.84), transparent 36%);
}

.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  padding: 0 clamp(18px, 4vw, 64px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: rgba(246, 248, 250, 0.84);
  border-bottom: 1px solid rgba(32, 37, 43, 0.1);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  transition: box-shadow .25s ease, background .25s ease;
}
.topbar.scrolled { background: rgba(250, 251, 252, 0.95); box-shadow: 0 8px 30px rgba(31, 42, 52, 0.09); }
.brand { display: flex; align-items: center; gap: 13px; text-decoration: none; white-space: nowrap; }
.brand img { display: block; width: 132px; height: auto; }
.brand span { font-family: 'ABeeZee', var(--sans); font-size: 12px; font-weight: 600; letter-spacing: .16em; }
.topbar-actions { display: flex; align-items: center; gap: 22px; min-width: 0; }
.section-nav { display: flex; align-items: center; gap: 4px; }
.section-nav a {
  padding: 8px 12px;
  color: var(--ink-soft);
  border-radius: 99px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
}
.section-nav a:hover, .section-nav a:focus-visible { background: rgba(47, 85, 122, .09); color: var(--blue-dark); }
.language-switch {
  display: flex;
  flex: none;
  padding: 3px;
  border: 1px solid rgba(32, 37, 43, 0.16);
  border-radius: 99px;
  background: rgba(255, 255, 255, .58);
}
.language-switch a {
  min-width: 42px;
  padding: 5px 10px;
  border-radius: 99px;
  color: var(--ink-soft);
  font-size: 12px;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
}
.language-switch a.active { background: var(--ink); color: #fff; }

.hero {
  position: relative;
  width: min(100% - 48px, 1320px);
  min-height: 100svh;
  margin: 0 auto;
  padding: calc(var(--header-height) + 80px) 0 90px;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(340px, .8fr);
  align-items: center;
  gap: clamp(60px, 9vw, 150px);
}
.hero-copy { max-width: 760px; }
.kicker, .eyebrow {
  margin: 0 0 18px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .24em;
  text-transform: uppercase;
}
.hero h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(64px, 7vw, 112px);
  font-style: italic;
  font-weight: 600;
  letter-spacing: -.045em;
  line-height: .91;
}
html[lang='zh-CN'] .hero h1 { font-family: var(--cn-serif); font-style: normal; font-weight: 900; letter-spacing: .02em; line-height: 1.08; }
.double-rule { width: min(520px, 78%); height: 7px; margin: 30px 0 24px; border-top: 2px solid var(--ink); border-bottom: 1px solid var(--ink); }
.hero-subtitle { margin: 0; color: var(--ink-soft); font-family: var(--serif); font-size: clamp(19px, 2vw, 27px); font-style: italic; line-height: 1.35; }
html[lang='zh-CN'] .hero-subtitle { font-family: var(--cn-serif); font-size: clamp(18px, 1.7vw, 24px); font-style: normal; font-weight: 600; letter-spacing: .12em; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.button {
  display: inline-flex;
  min-height: 46px;
  padding: 0 22px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ink);
  border-radius: 2px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .08em;
  text-decoration: none;
  text-transform: uppercase;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.button:hover { transform: translateY(-2px); }
.button-primary { color: #fff; background: var(--ink); box-shadow: 0 10px 22px rgba(32, 37, 43, .15); }
.button-quiet { background: rgba(255, 255, 255, .35); }
.glass-card {
  border: 1px solid rgba(255, 255, 255, .82);
  background: var(--glass);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}
.hero-card { padding: clamp(34px, 5vw, 66px); }
.hero-date { margin: 0; font-family: var(--serif); font-size: clamp(31px, 3vw, 47px); font-style: italic; line-height: 1.15; }
html[lang='zh-CN'] .hero-date { font-family: var(--cn-serif); font-style: normal; font-weight: 700; }
.hero-time { margin: 28px 0 4px; font-size: clamp(22px, 2.2vw, 32px); font-weight: 700; letter-spacing: -.02em; }
.hero-time span { color: var(--blue); font-size: .55em; letter-spacing: .12em; }
.local-time { margin-top: 7px; color: var(--blue-dark); font-size: 13px; font-weight: 600; line-height: 1.45; }
.local-time::before { content: '◷'; margin-right: 7px; }
.mini-rule { width: 54px; height: 1px; margin: 28px 0 20px; background: var(--ink); }
.hero-mode { margin: 0; color: var(--ink-soft); font-size: 14px; font-weight: 600; }
.scroll-cue {
  position: absolute;
  bottom: 26px;
  left: 50%;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: .16em;
  text-decoration: none;
  text-transform: uppercase;
  transform: translateX(-50%);
}
.scroll-cue span { width: 34px; height: 1px; background: currentColor; }

.content-shell { padding-bottom: 100px; }
.section {
  width: min(100% - 48px, 1180px);
  margin: 0 auto 32px;
  padding: clamp(42px, 6vw, 82px);
  background: rgba(245, 247, 249, .86);
  border: 1px solid rgba(255, 255, 255, .75);
  box-shadow: var(--shadow);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}
.section-heading { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: end; gap: 30px; margin-bottom: 46px; }
.section-index { margin: 0 0 8px; color: var(--blue); font-size: 12px; font-weight: 700; letter-spacing: .22em; }
.section h2 { margin: 0; font-family: var(--serif); font-size: clamp(34px, 5vw, 63px); font-style: italic; font-weight: 600; letter-spacing: -.035em; line-height: 1.05; }
html[lang='zh-CN'] .section h2 { font-family: var(--cn-serif); font-size: clamp(32px, 4.2vw, 54px); font-style: normal; font-weight: 800; letter-spacing: .02em; }
.section-summary { max-width: 480px; margin: 15px 0 0; color: var(--ink-soft); font-size: 15px; }
.date-chip { padding: 13px 16px; border: 1px solid var(--line); color: var(--ink-soft); font-size: 13px; font-weight: 600; text-align: right; }

.attend-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.detail-card { padding: 30px; border: 1px solid var(--line); background: rgba(255, 255, 255, .48); }
.detail-card.featured { color: #fff; border-color: var(--ink); background: var(--ink); }
.detail-card .label { margin: 0 0 12px; color: var(--blue); font-size: 11px; font-weight: 700; letter-spacing: .17em; text-transform: uppercase; }
.detail-card.featured .label { color: #b9d0e3; }
.detail-card h3 { margin: 0 0 10px; font-family: var(--serif); font-size: 25px; font-style: italic; line-height: 1.25; }
html[lang='zh-CN'] .detail-card h3 { font-family: var(--cn-serif); font-style: normal; }
.detail-card p, .detail-card address { margin: 0; color: var(--ink-soft); font-size: 14px; font-style: normal; }
.detail-card.featured p { color: #e3e8ec; }
.meeting-id { display: block; margin: 13px 0 7px; font-size: clamp(25px, 3vw, 39px); font-weight: 700; letter-spacing: .04em; }
.facts { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 20px; }
.fact { padding: 18px; border-top: 1px solid var(--line); }
.fact strong { display: block; margin-bottom: 5px; font-size: 13px; }
.fact span { color: var(--muted); font-size: 12px; }

.session-access {
  display: grid;
  grid-template-columns: minmax(250px, .8fr) minmax(0, 1.2fr);
  gap: clamp(28px, 5vw, 64px);
  margin: -8px 0 48px;
  padding: clamp(25px, 4vw, 38px);
  color: #fff;
  background: var(--ink);
}
.session-access .label { margin: 0 0 9px; color: #b9d0e3; font-size: 11px; font-weight: 700; letter-spacing: .17em; }
.session-access h3 { margin: 0; font-family: var(--cn-serif); font-size: 23px; }
.session-access .meeting-id { margin-bottom: 0; }
.session-access-simple { grid-template-columns: 1fr; }
.session-access-simple .session-access-primary { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: end; gap: 2px 28px; }
.session-access-simple .label { grid-column: 1 / -1; }
.session-access-simple .meeting-id { margin: 0; }
.session-access-details { display: grid; align-content: center; gap: 13px; margin: 0; }
.session-access-details div { display: grid; grid-template-columns: 92px minmax(0, 1fr); gap: 16px; padding-bottom: 12px; border-bottom: 1px solid rgba(255, 255, 255, .16); }
.session-access-details div:last-child { padding-bottom: 0; border-bottom: 0; }
.session-access-details dt { color: #9eb8cd; font-size: 12px; font-weight: 700; }
.session-access-details dd { margin: 0; color: #eef3f7; font-size: 14px; }

.agenda { position: relative; }
.agenda::before { content: ''; position: absolute; top: 15px; bottom: 15px; left: 166px; width: 1px; background: var(--line); }
.agenda-item { position: relative; display: grid; grid-template-columns: 138px minmax(0, 1fr); gap: 56px; padding: 0 0 34px; }
.agenda-item:last-child { padding-bottom: 0; }
.agenda-time { padding-top: 3px; color: var(--blue-dark); font-size: 14px; font-weight: 700; text-align: right; }
.agenda-time span { display: block; color: var(--muted); font-size: 10px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; }
.agenda-body { position: relative; padding: 0 0 30px 32px; border-bottom: 1px solid var(--line); }
.agenda-item:last-child .agenda-body { border-bottom: 0; padding-bottom: 0; }
.agenda-body::before { content: ''; position: absolute; top: 8px; left: -32px; width: 9px; height: 9px; border: 3px solid var(--paper); border-radius: 50%; background: var(--blue); box-shadow: 0 0 0 1px var(--blue); }
.agenda-title { margin: 0; font-family: var(--serif); font-size: clamp(23px, 2.4vw, 31px); font-style: italic; line-height: 1.2; }
html[lang='zh-CN'] .agenda-title { font-family: var(--cn-serif); font-style: normal; font-weight: 700; }
.agenda-meta { margin: 7px 0 0; color: var(--blue); font-size: 13px; font-weight: 600; }
.agenda-points { display: grid; gap: 6px; margin: 16px 0 0; padding: 0; list-style: none; }
.agenda-points li { position: relative; padding-left: 17px; color: var(--ink-soft); font-size: 14px; }
.agenda-points li::before { content: '—'; position: absolute; left: 0; color: #98a2ac; }

.topic-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.topic-card { min-height: 210px; padding: 27px; border: 1px solid var(--line); background: rgba(255, 255, 255, .48); }
.topic-number { color: var(--blue); font-family: var(--serif); font-size: 32px; font-style: italic; }
.topic-card h3 { margin: 12px 0 14px; font-family: var(--cn-serif); font-size: 19px; line-height: 1.35; }
.topic-card ul { margin: 0; padding-left: 18px; color: var(--ink-soft); font-size: 13px; }

.notice { margin: -18px 0 30px; padding: 14px 18px; color: #654e24; border: 1px solid rgba(155, 116, 41, .25); background: rgba(255, 244, 214, .56); font-size: 13px; }
.city-tabs { display: flex; gap: 7px; margin-bottom: 28px; padding-bottom: 1px; overflow-x: auto; }
.city-tabs { scrollbar-width: none; }
.city-tabs::-webkit-scrollbar { display: none; }
.city-tab { flex: 1; min-width: 100px; padding: 12px 16px; border: 1px solid var(--line); color: var(--ink-soft); background: rgba(255, 255, 255, .46); font: 600 14px var(--sans); cursor: pointer; }
.city-tab.active { color: #fff; border-color: var(--ink); background: var(--ink); }
.city-panel { display: none; }
.city-panel.active { display: block; }
.city-panel .agenda::before { left: 146px; }
.city-panel .agenda-item { grid-template-columns: 118px minmax(0, 1fr); }

.site-footer { padding: 20px 24px 55px; color: var(--ink-soft); text-align: center; }
.site-footer img { width: 170px; height: auto; opacity: .9; }
.site-footer p { margin: 10px 0 0; font-size: 12px; letter-spacing: .08em; }

.reveal { opacity: 0; transform: translateY(18px); animation: reveal .7s ease forwards; }
.hero-card.reveal { animation-delay: .18s; }
@keyframes reveal { to { opacity: 1; transform: translateY(0); } }

@media (max-width: 980px) {
  :root { --header-height: 72px; }
  .section-nav { display: none; }
  .hero { grid-template-columns: 1fr 340px; gap: 40px; }
  .brand span { display: none; }
  .topic-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 820px) {
  .topbar { padding: 0 16px; }
  .topbar-actions { gap: 10px; }
  .brand img { width: 112px; }
  .hero {
    width: min(100% - 32px, 560px);
    min-height: auto;
    padding: calc(var(--header-height) + 60px) 0 86px;
    grid-template-columns: 1fr;
    gap: 38px;
    text-align: center;
  }
  .hero-copy { display: flex; flex-direction: column; align-items: center; }
  .hero h1 { font-size: clamp(51px, 15vw, 78px); }
  .double-rule { margin: 24px auto 20px; }
  .hero-actions { justify-content: center; }
  .hero-card { width: 100%; padding: 34px 28px; text-align: left; }
  .scroll-cue { display: none; }
  .section { width: min(100% - 24px, 640px); padding: 38px 20px; margin-bottom: 18px; }
  .section h2,
  html[lang='zh-CN'] .section h2 { font-size: 30px; line-height: 1.14; }
  .section-heading { grid-template-columns: 1fr; margin-bottom: 34px; }
  .date-chip { text-align: left; }
  .attend-grid { grid-template-columns: 1fr; }
  .facts { grid-template-columns: 1fr; }
  .fact { padding: 12px 0; }
  .session-access { grid-template-columns: 1fr; gap: 24px; margin-bottom: 38px; }
  .session-access-simple .session-access-primary { grid-template-columns: 1fr; }
  .session-access-simple .meeting-id { margin-top: 10px; }
  .agenda::before, .city-panel .agenda::before { left: 5px; }
  .agenda-item, .city-panel .agenda-item { grid-template-columns: 1fr; gap: 9px; padding-left: 29px; }
  .agenda-time { text-align: left; }
  .agenda-time span { display: inline; margin-left: 6px; }
  .agenda-body { padding-left: 0; }
  .agenda-body::before { top: -27px; left: -28px; }
  .topic-grid { grid-template-columns: 1fr; }
  .topic-card { min-height: 0; }
  .city-tab { min-width: 0; padding-inline: 10px; }
}

@media (max-width: 420px) {
  .language-switch a { min-width: 38px; padding-inline: 7px; }
  .hero { padding-top: calc(var(--header-height) + 43px); }
  .hero-actions { width: 100%; }
  .button { flex: 1; padding-inline: 12px; font-size: 11px; }
  .detail-card { padding: 24px 20px; }
  .meeting-id { font-size: 25px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}