@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;600;700&family=IBM+Plex+Sans+JP:wght@400;600;700&display=swap");

:root {
  --color-bg: #ffffff;
  --color-text: #111111;
  --color-muted: #555555;
  --color-border: #d8d8d8;
  --color-subtle: #f5f5f5;
  --color-tint: #edf7f1;
  --max-width: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: "IBM Plex Sans JP", "IBM Plex Sans", -apple-system,
    BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN",
    "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.7;
}

main {
  flex: 1 0 auto;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--color-border);
  background: rgba(237, 247, 241, 0.96);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 28px;
  width: min(100% - 40px, var(--max-width));
  min-height: 76px;
  margin: 0 auto;
}

.site-title {
  display: grid;
  flex: 0 1 auto;
  min-width: 0;
  line-height: 1.2;
}

.site-title-main {
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: 0;
}

.site-title-sub {
  margin-top: 4px;
  color: var(--color-muted);
  font-size: 0.82rem;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  flex: 1 1 auto;
  font-size: 0.95rem;
  white-space: nowrap;
}

.site-nav a,
.language-switch a {
  border-bottom: 1px solid transparent;
}

.site-nav a:hover,
.site-nav a[aria-current="page"],
.language-switch a:hover,
.language-switch .active {
  border-bottom-color: currentColor;
}

.site-nav a[aria-current="page"] {
  font-weight: 600;
}

.language-switch {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--color-muted);
  font-size: 0.85rem;
  white-space: nowrap;
}

.language-switch .active {
  color: var(--color-text);
  font-weight: 600;
}

.section {
  padding: 72px 0;
}

.section[id] {
  scroll-margin-top: 28px;
}

.section-muted {
  background: var(--color-subtle);
}

.section-inner {
  width: min(100% - 40px, var(--max-width));
  margin: 0 auto;
}

.hero {
  display: flex;
  align-items: flex-start;
  min-height: 280px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-tint);
  padding: 56px 0 64px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--color-muted);
  font-size: 0.92rem;
  font-weight: 700;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 100%;
  margin-bottom: 22px;
  font-size: clamp(2rem, 4.2vw, 3.6rem);
  line-height: 1.18;
  letter-spacing: 0;
}

html[lang="ja"] .hero h1 {
  font-size: clamp(1.85rem, 3.6vw, 3.1rem);
}

html[lang="en"] .hero h1 {
  font-size: clamp(1.8rem, 2.35vw, 2.15rem);
  white-space: nowrap;
}

html[lang="en"] .site-title-sub {
  font-size: 0.76rem;
  white-space: nowrap;
}

.page-title {
  margin-bottom: 28px;
  font-size: clamp(2rem, 3vw, 2.8rem);
  white-space: normal;
}

h2 {
  margin-bottom: 18px;
  font-size: 1.65rem;
  line-height: 1.35;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.lead {
  max-width: 760px;
  color: var(--color-muted);
  font-size: 1.08rem;
}

.about-section {
  padding-bottom: 40px;
}

.themes-section {
  padding-top: 40px;
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  gap: 56px;
  align-items: start;
}

.notice-box {
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background: var(--color-bg);
  padding: 24px;
}

.simple-list {
  margin: 0;
  padding-left: 1.2em;
}

.simple-list li + li {
  margin-top: 8px;
}

.schedule-table {
  width: 100%;
  margin-top: 28px;
  border-collapse: collapse;
  background: var(--color-bg);
}

.schedule-table th,
.schedule-table td {
  border: 1px solid var(--color-border);
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
}

.schedule-table th {
  background: var(--color-subtle);
  font-weight: 700;
}

.table-link {
  border-bottom: 1px solid currentColor;
  font-weight: 600;
}

.link-separator {
  margin: 0 8px;
  color: var(--color-muted);
}

.event-list {
  display: grid;
  gap: 12px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.event-list li {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--color-border);
  padding: 16px 0;
}

.event-list span:last-child {
  color: var(--color-muted);
}

.text-link {
  display: inline-block;
  margin-top: 8px;
  border-bottom: 1px solid currentColor;
  font-weight: 600;
}

.member-list {
  display: grid;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background: var(--color-bg);
  padding: 24px;
}

.member-role {
  margin: 0;
  color: var(--color-muted);
  font-weight: 700;
}

.member-row h4,
.secretary-row h4 {
  margin: 0;
  font-size: 1rem;
}

.member-row p,
.secretary-row p {
  margin: 0;
  color: var(--color-muted);
}

.member-table {
  display: grid;
  border-top: 1px solid var(--color-border);
}

.member-row {
  display: grid;
  grid-template-columns: 96px 160px minmax(180px, 1fr);
  gap: 18px;
  align-items: start;
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
}

.member-subgroup {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 18px;
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
}

.secretary-list {
  display: grid;
  gap: 12px;
}

.secretary-row {
  display: grid;
  grid-template-columns: 160px minmax(180px, 1fr);
  gap: 18px;
}

.site-footer {
  flex-shrink: 0;
  border-top: 1px solid var(--color-border);
  padding: 28px 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 24px;
}

.footer-inner p {
  margin: 0;
}

@media (max-width: 1100px) {
  .header-inner {
    flex-wrap: wrap;
    gap: 14px 22px;
    padding: 14px 0;
  }

  .site-title {
    flex: 1 1 100%;
  }

  .site-nav {
    justify-content: flex-start;
    order: 3;
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .language-switch {
    margin-left: auto;
  }

  .two-column {
    grid-template-columns: 1fr;
  }

  .member-row,
  .member-subgroup,
  .secretary-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .secretary-list {
    gap: 10px;
  }

  .hero {
    min-height: 240px;
    padding: 48px 0 56px;
  }

  .section[id] {
    scroll-margin-top: 92px;
  }
}

@media (max-width: 560px) {
  .header-inner,
  .section-inner {
    width: min(100% - 28px, var(--max-width));
  }

  .section {
    padding: 52px 0;
  }

  .section[id] {
    scroll-margin-top: 96px;
  }

  .about-section {
    padding-bottom: 32px;
  }

  .themes-section {
    padding-top: 32px;
  }

  .site-title-sub {
    font-size: 0.76rem;
  }

  .site-nav {
    gap: 16px;
    font-size: 0.88rem;
  }

  h1 {
    font-size: 2rem;
    white-space: normal;
  }

  html[lang="en"] .hero h1 {
    white-space: normal;
  }

  .schedule-table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }

  .event-list li,
  .footer-inner {
    display: grid;
  }
}