:root {
  --bg: #f7f8f6;
  --surface: #ffffff;
  --ink: #202124;
  --muted: #646a73;
  --line: #d9dee5;
  --accent: #0f766e;
  --accent-strong: #134e4a;
  --warm: #a4491f;
  --soft: #eef6f4;
  --shadow: 0 16px 40px rgba(31, 41, 55, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", "Noto Sans", "Microsoft YaHei", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.62;
}

a {
  color: var(--accent-strong);
  text-decoration: none;
  text-underline-offset: 0.18em;
}

a:hover,
a:focus {
  text-decoration: underline;
}

.wrap {
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
}

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

.brand {
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  font-size: 0.94rem;
}

.hero {
  background: linear-gradient(180deg, #ffffff 0%, #f7f8f6 100%);
  border-bottom: 1px solid var(--line);
  padding: 52px 0 36px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.2;
  letter-spacing: 0;
}

h1 {
  max-width: 820px;
  font-size: clamp(2.1rem, 4vw, 3.7rem);
}

h2 {
  font-size: clamp(1.55rem, 2.5vw, 2.25rem);
}

h3 {
  font-size: 1.18rem;
}

.lead {
  max-width: 780px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 28px;
  margin-top: 24px;
  color: var(--muted);
  font-size: 0.98rem;
}

.section {
  padding: 42px 0;
}

.section + .section {
  border-top: 1px solid var(--line);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 20px;
}

.section-note {
  max-width: 640px;
  margin: 8px 0 0;
  color: var(--muted);
}

.notice {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 22px 24px;
}

.notice p {
  margin: 0;
}

.talk-list {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.talk {
  display: grid;
  grid-template-columns: minmax(150px, 210px) 1fr;
  gap: 24px;
  padding: 24px;
}

.talk + .talk {
  border-top: 1px solid var(--line);
}

.talk-date {
  color: var(--accent-strong);
  font-weight: 700;
}

.talk-time,
.talk-place,
.talk-note {
  color: var(--muted);
  font-size: 0.95rem;
}

.speaker {
  margin-bottom: 4px;
  color: var(--warm);
  font-weight: 700;
}

.title {
  margin: 0 0 10px;
  font-size: 1.06rem;
  font-weight: 700;
}

.abstract {
  margin: 0;
  color: #34383f;
}

.abstract + .abstract {
  margin-top: 10px;
}

.empty {
  color: var(--muted);
  font-style: italic;
}

.archive-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 10px 16px;
}

.archive-heading {
  display: block;
  margin: 26px 0 12px;
  color: var(--accent-strong);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: 0;
}

.archive-heading-spaced {
  margin-top: 34px;
}

.archive-link {
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  font-weight: 600;
  padding: 11px 14px;
}

.archive-link:hover,
.archive-link:focus {
  border-color: var(--accent);
  color: var(--accent-strong);
  text-decoration: none;
}

.people-lines {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 2px 22px;
}

.people-row {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 18px;
  padding: 16px 0;
}

.people-row + .people-row {
  border-top: 1px solid var(--line);
}

.people-label {
  color: var(--warm);
  font-weight: 700;
}

.member-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
}

.member-list a,
.member-list span {
  white-space: nowrap;
}

.back-link {
  display: inline-block;
  margin-bottom: 18px;
  font-weight: 700;
}

.site-footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
  padding: 28px 0 40px;
  font-size: 0.92rem;
}

@media (max-width: 720px) {
  .wrap {
    width: min(100% - 28px, 1120px);
  }

  .topbar,
  .section-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    padding-top: 36px;
  }

  .talk {
    grid-template-columns: 1fr;
    gap: 12px;
    padding: 20px 18px;
  }

  .people-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .member-list a,
  .member-list span {
    white-space: normal;
  }
}