:root {
  --ink: #163c39;
  --teal: #075c57;
  --muted: #536b67;
  --paper: #f8f9f5;
  --lime: #def39a;
  --line: #d8e2dc;
  --width: 1160px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 100px; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif; line-height: 1.85; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
img { display: block; max-width: 100%; height: auto; }
h1, h2, h3, p, figure { margin: 0; }
h1, h2, h3 { line-height: 1.5; }
a, button, summary { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid #b55217; outline-offset: 5px; }
.container { width: min(var(--width), calc(100% - 96px)); margin-inline: auto; }
.skip-link { position: fixed; top: -100px; left: 16px; z-index: 100; background: white; padding: 12px 24px; }
.skip-link:focus { top: 12px; }
.site-header { position: sticky; top: 0; z-index: 20; background: rgba(248, 249, 245, .97); border-bottom: 1px solid var(--line); }
.header-inner { min-height: 88px; max-width: 1440px; margin: auto; padding: 14px 48px; display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.brand { display: inline-flex; align-items: center; gap: 12px; font-size: 15px; font-weight: 600; line-height: 1.25; flex-shrink: 0; }
.brand strong { display: block; font-size: 23px; letter-spacing: -.04em; }
.brand-symbol { font-family: monospace; font-size: 27px; font-weight: 700; color: var(--teal); background: #e7eee2; width: 48px; height: 48px; display: grid; place-items: center; border-radius: 50%; letter-spacing: -.1em; }
.navigation { display: flex; align-items: center; gap: 28px; font-size: 13px; font-weight: 700; }
.navigation a { transition: color .2s; }
.navigation a:hover { color: #26756d; }
.navigation .nav-cta { background: var(--teal); color: white; padding: 11px 20px; border-radius: 4px; }
.nav-cta span { margin-left: 12px; }
.navigation .nav-cta:hover { background: #164e47; }
.menu-toggle { display: none; }
.hero { position: relative; min-height: 660px; color: white; display: flex; align-items: center; isolation: isolate; overflow: hidden; }
.hero-image, .hero-shade { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -1; }
.hero-image { object-fit: cover; object-position: center 68%; }
.hero-shade { background: linear-gradient(90deg, rgba(8, 39, 40, .83), rgba(8, 39, 40, .46) 53%, rgba(8, 39, 40, .08)); }
.hero-content { padding-block: 76px 112px; }
.eyebrow { font-family: Arial, sans-serif; font-weight: 700; font-size: 11px; letter-spacing: .18em; line-height: 1.5; color: var(--teal); margin-bottom: 20px; }
.eyebrow.light { color: var(--lime); }
.hero h1 { font-size: clamp(40px, 4.9vw, 68px); letter-spacing: .045em; font-weight: 800; line-height: 1.45; margin-bottom: 26px; }
.hero-description { font-size: 16px; line-height: 2; letter-spacing: .04em; }
.hero-actions { display: flex; gap: 30px; align-items: center; flex-wrap: wrap; margin-top: 34px; }
.button { display: inline-flex; align-items: center; justify-content: space-between; gap: 32px; min-height: 56px; padding: 16px 26px; border-radius: 4px; font-size: 14px; font-weight: 700; transition: background .2s, transform .2s; }
.button-lime { color: var(--ink); background: var(--lime); }
.button-lime:hover { background: #cde879; transform: translateY(-2px); }
.hero-link { font-size: 13px; border-bottom: 1px solid #a4b6ac; padding-block: 10px; }
.hero-link span { margin-left: 20px; }
.hero-bottom { position: absolute; bottom: 27px; left: 0; right: 0; display: flex; justify-content: space-between; align-items: center; font-size: 11px; letter-spacing: .08em; color: #e5ece7; }
.hero-location { font-family: Arial, sans-serif; font-size: 10px; letter-spacing: .18em; }
.mobile-break { display: none; }
.section { padding-block: 88px; }
.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 32px; margin-bottom: 36px; }
.section-heading .eyebrow { margin-bottom: 12px; }
h2 { font-size: clamp(25px, 2.55vw, 34px); letter-spacing: -.035em; font-weight: 700; }
.text-link { display: inline-flex; gap: 24px; align-items: center; font-size: 13px; font-weight: 700; border-bottom: 1px solid var(--ink); padding-bottom: 6px; flex-shrink: 0; }
.text-link:hover { color: var(--teal); border-color: var(--teal); }
.events-section { background: #eef2e9; padding-block: 60px; }
.event-feature { display: flex; align-items: stretch; background: white; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.event-feature-connpass { flex-direction: column; }
.event-content { display: flex; align-items: stretch; min-width: 0; }
.event-eyecatch-link { display: block; background: #edf2ed; border-bottom: 1px solid var(--line); }
.event-eyecatch { display: block; width: 100%; height: clamp(180px, 24vw, 280px); object-fit: contain; }
.event-history-image { width: 100px; height: auto; aspect-ratio: 1200 / 630; object-fit: contain; background: #edf2ed; border-radius: 3px; flex-shrink: 0; }
.event-date { width: 152px; flex-shrink: 0; margin-block: 30px; border-right: 1px solid var(--line); display: flex; flex-direction: column; justify-content: center; align-items: center; font-family: Arial, sans-serif; }
.event-date span { font-size: 11px; letter-spacing: .1em; }
.event-date strong { font-size: 66px; line-height: 1.15; font-weight: 500; }
.event-body { padding: 30px 32px; flex: 1; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.tag { color: var(--teal); font-size: 10px; font-weight: 700; background: #e6eee5; padding: 3px 10px; border: 1px solid #e6eee5; border-radius: 2px; }
.tag-outline { background: transparent; border-color: var(--line); color: var(--muted); }
.event-body h3 { font-size: 22px; margin-bottom: 10px; }
.event-body > p { font-size: 13px; color: var(--muted); }
.event-meta { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 16px; font-size: 12px; font-weight: 700; }
.event-body .event-organizer { font-size: 11px; margin-top: 8px; }
.event-link { display: flex; flex-direction: column; justify-content: center; font-size: 13px; font-weight: 700; padding: 28px; background: #fafbf8; border-left: 1px solid var(--line); }
.event-link span { font-size: 11px; font-weight: 400; color: var(--muted); }
.event-link:hover { background: #edf4e2; }
.section-note { font-size: 11px; color: var(--muted); margin-top: 16px; }
.event-group-heading { font-size: 17px; margin: 30px 0 16px; }
.connpass-events { display: grid; gap: 16px; }
.event-empty { padding: 24px; background: white; border: 1px solid var(--line); font-size: 13px; }
.event-history { margin-top: 24px; }
.event-history summary { cursor: pointer; font-size: 13px; font-weight: 700; padding: 12px 0; }
.event-history ul { list-style: none; margin: 0; padding: 0; }
.event-history li { border-top: 1px solid var(--line); }
.event-history a { display: flex; align-items: baseline; gap: 20px; padding: 14px 0; font-size: 13px; }
.event-history a:hover { color: var(--teal); }
.event-history time { flex-shrink: 0; font-family: Arial, sans-serif; font-size: 11px; color: var(--muted); }
.event-history span:last-child { margin-left: auto; }
.feed-warning { color: #834817; }
.about-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 68px; }
.about-intro h2 { font-size: clamp(26px, 2.5vw, 34px); line-height: 1.8; }
.about-copy > p { margin-bottom: 20px; font-size: 14px; }
.about-copy .lead { font-size: 18px; font-weight: 700; }
.civic-note { border-left: 3px solid var(--teal); padding-left: 20px; margin-top: 30px; }
.small-label { font-size: 11px; font-weight: 700; color: var(--teal); }
.civic-note p { font-size: 12px; color: var(--muted); margin-top: 8px; }
.activities-section { border-top: 1px solid var(--line); }
.heading-description { font-size: 13px; color: var(--muted); }
.activities-layout { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.community-photo img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; border-radius: 4px; }
.community-photo figcaption { font-size: 11px; color: var(--muted); margin-top: 12px; }
.activity-list article { display: flex; gap: 24px; padding-block: 24px; border-bottom: 1px solid var(--line); }
.activity-list article:first-child { padding-top: 0; }
.activity-list article:last-child { border: 0; }
.activity-number { font-family: Arial, sans-serif; font-size: 12px; color: var(--teal); padding-top: 6px; }
.activity-list h3 { font-size: 21px; margin-bottom: 10px; }
.activity-list p { font-size: 13px; color: var(--muted); }
.activity-example { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 32px; padding: 30px 0; border-block: 1px solid var(--line); margin-top: 48px; }
.activity-example h3 { font-size: 17px; margin-bottom: 6px; }
.activity-example p { font-size: 12px; color: var(--muted); }
.example-date { font-size: 11px; color: var(--muted); }
.first-section { background: #edf2ed; }
.projects-section { border-top: 1px solid var(--line); background: #fff; }
.projects-intro { font-size: 14px; color: var(--muted); margin: -12px 0 28px; }
.project-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.project-card { display: flex; flex-direction: column; padding: 28px; background: var(--paper); border: 1px solid var(--line); border-radius: 5px; transition: border-color .2s, transform .2s; }
.project-card:hover { border-color: var(--teal); transform: translateY(-3px); }
.project-main-link { display: flex; flex-direction: column; flex: 1; }
.project-eyecatch { display: block; width: 100%; height: auto; aspect-ratio: 1200 / 630; object-fit: contain; background: #edf2ed; border-radius: 3px; margin-bottom: 24px; }
.project-source-link { font-size: 11px; color: var(--muted); margin-top: 16px; align-self: start; }
.project-source-link:hover, .repository-source-link:hover { color: var(--teal); text-decoration: underline; }
.project-card-number { font-family: Arial, sans-serif; font-size: 11px; letter-spacing: .12em; color: var(--teal); }
.project-card h3 { margin: 20px 0 12px; font-size: 21px; overflow-wrap: anywhere; }
.project-card p { font-size: 13px; color: var(--muted); margin-bottom: 24px; }
.project-card-bottom { margin-top: auto; padding-top: 20px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; align-items: center; gap: 12px; font-size: 11px; }
.project-card time { color: var(--muted); }
.project-card-bottom > span { font-weight: 700; white-space: nowrap; }
.project-page-hero { background: #eef2e9; padding: 36px 0 64px; }
.breadcrumbs { display: flex; gap: 16px; font-size: 11px; color: var(--muted); margin-bottom: 42px; }
.breadcrumbs a:hover { text-decoration: underline; }
.project-page-hero h1 { font-size: clamp(34px, 5vw, 52px); margin-bottom: 22px; }
.project-page-description { font-size: 15px; margin-bottom: 28px; }
.repository-list { list-style: none; margin: 0; padding: 0; }
.repository-list li { border-top: 1px solid var(--line); }
.repository-list li:last-child { border-bottom: 1px solid var(--line); }
.repository-link { display: flex; justify-content: space-between; align-items: center; gap: 24px; padding: 22px 0; }
.repository-link:hover { color: var(--teal); }
.repository-source-link { display: inline-block; font-size: 11px; color: var(--muted); margin: -8px 0 20px; }
.repository-name { display: block; font-size: 17px; font-weight: 700; overflow-wrap: anywhere; }
.repository-description { display: block; color: var(--muted); font-size: 12px; margin-top: 6px; overflow-wrap: anywhere; }
.repository-meta { display: flex; align-items: center; flex-shrink: 0; gap: 20px; font-size: 11px; color: var(--muted); }
.repository-badges { display: inline-flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.repository-meta .repository-destination { font-size: 11px; font-weight: 700; color: var(--teal); }
.navigation a[aria-current="page"] { text-decoration: underline; text-underline-offset: 5px; }
.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 36px; }
.steps li { border-top: 2px solid var(--teal); padding-top: 20px; }
.step-number { font-family: Arial, sans-serif; font-size: 11px; letter-spacing: .12em; color: var(--teal); }
.steps h3 { margin-top: 18px; margin-bottom: 12px; font-size: 18px; }
.steps p { font-size: 13px; color: var(--muted); }
.faq-layout { display: grid; grid-template-columns: 1fr 2fr; gap: 52px; margin-top: 68px; }
.faq-layout > h3 { font-size: 19px; padding-top: 18px; }
.faq-list details { border-bottom: 1px solid #cbd8ce; }
.faq-list details:first-child { border-top: 1px solid #cbd8ce; }
.faq-list summary { cursor: pointer; padding: 18px 32px 18px 0; font-size: 13px; font-weight: 700; list-style: none; position: relative; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 4px; font-size: 22px; top: 12px; color: var(--teal); }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { padding-bottom: 20px; font-size: 13px; color: var(--muted); }
.join-section { background: var(--teal); color: white; padding-block: 72px; }
.join-layout { display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.join-layout h2 { font-size: clamp(25px, 2.8vw, 36px); line-height: 1.7; }
.join-layout p:last-child { font-size: 13px; margin-top: 20px; color: #dce8e2; }
.join-layout .button { flex-shrink: 0; }
.follow-section { padding-block: 56px; }
.follow-layout { display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.follow-layout .eyebrow { margin-bottom: 10px; }
.follow-layout h2 { font-size: 22px; }
.social-links { display: flex; flex-wrap: wrap; gap: 18px; }
.social-links a { min-width: 150px; border: 1px solid var(--line); border-radius: 4px; padding: 15px 20px; display: flex; justify-content: space-between; align-items: center; gap: 32px; font-family: Arial, sans-serif; font-size: 14px; font-weight: 700; }
.social-links a:hover { border-color: var(--teal); background: #edf2e9; }
.site-footer { border-top: 1px solid var(--line); padding-block: 28px; }
.footer-layout { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 20px; }
.site-footer .brand { font-size: 11px; }
.site-footer .brand strong { font-size: 17px; }
.site-footer .brand-symbol { font-size: 20px; width: 36px; height: 36px; }
.site-footer p, .site-footer small { font-size: 10px; color: var(--muted); }
@media (min-width: 1500px) { .hero { min-height: 740px; } }
@media (max-width: 1050px) {
  .header-inner { padding-inline: 28px; gap: 20px; }
  .navigation { gap: 16px; font-size: 12px; }
  .container { width: calc(100% - 64px); }
  .event-link { padding: 20px; }
  .about-layout, .activities-layout { gap: 36px; }
  .activity-example { gap: 24px; }
}
@media (max-width: 900px) {
  .header-inner { min-height: 76px; flex-wrap: wrap; gap: 0; padding: 14px 24px; }
  .menu-toggle:not([hidden]) { display: flex; align-items: center; gap: 12px; border: 1px solid var(--line); background: transparent; color: var(--ink); padding: 8px 12px; border-radius: 4px; font-size: 12px; cursor: pointer; }
  .navigation { flex-basis: 100%; flex-direction: column; align-items: stretch; gap: 0; margin-top: 16px; }
  .navigation a { padding: 14px 0; border-top: 1px solid var(--line); }
  .navigation .nav-cta { margin-top: 12px; padding: 12px 16px; }
  .js-enabled .navigation:not(.is-open) { display: none; }
  .project-grid { grid-template-columns: 1fr; }
  .repository-link { align-items: start; }
  .repository-meta { flex-direction: column; align-items: end; gap: 4px; }
}
@media (max-width: 800px) {
  html { scroll-padding-top: 90px; }
  .header-inner { min-height: 76px; flex-wrap: wrap; gap: 0; padding: 14px 24px; }
  .brand { font-size: 12px; }
  .brand strong { font-size: 19px; }
  .brand-symbol { width: 42px; height: 42px; font-size: 23px; }
  .menu-toggle:not([hidden]) { display: flex; align-items: center; gap: 12px; border: 1px solid var(--line); background: transparent; color: var(--ink); padding: 8px 12px; border-radius: 4px; font-size: 12px; cursor: pointer; }
  .navigation { flex-basis: 100%; flex-direction: column; align-items: stretch; gap: 0; margin-top: 16px; }
  .navigation a { padding: 14px 0; border-top: 1px solid var(--line); }
  .navigation .nav-cta { margin-top: 12px; padding: 12px 16px; }
  .js-enabled .navigation:not(.is-open) { display: none; }
  .container { width: calc(100% - 48px); }
  .hero { min-height: 600px; }
  .hero-content { padding-block: 64px 108px; }
  .hero h1 { font-size: clamp(34px, 6.5vw, 52px); }
  .hero-shade { background: linear-gradient(90deg, rgba(8, 39, 40, .84), rgba(8, 39, 40, .38)); }
  .hero-description { font-size: 14px; }
  .hero-actions { gap: 24px; }
  .section { padding-block: 60px; }
  .section-heading { align-items: start; flex-direction: column; gap: 20px; }
  .event-feature { flex-wrap: wrap; }
  .event-content { flex-wrap: wrap; }
  .event-history a { flex-wrap: wrap; align-items: center; gap: 10px 14px; }
  .event-history-image { width: 80px; }
  .event-date { width: 100px; margin-block: 24px; }
  .event-date strong { font-size: 52px; }
  .event-body { padding: 24px; flex-basis: calc(100% - 100px); }
  .event-body h3 { font-size: 19px; }
  .event-link { width: 100%; flex-direction: row; gap: 24px; justify-content: space-between; align-items: center; border-left: 0; border-top: 1px solid var(--line); padding: 18px 24px; }
  .event-link br { display: none; }
  .about-layout, .activities-layout { grid-template-columns: 1fr; }
  .about-layout { gap: 28px; }
  .community-photo img { aspect-ratio: 16 / 10; }
  .activity-example { grid-template-columns: 1fr; gap: 12px; }
  .activity-example .text-link { justify-self: start; margin-top: 4px; }
  .steps { gap: 22px; }
  .steps h3 { font-size: 16px; }
  .faq-layout { grid-template-columns: 1fr; gap: 20px; margin-top: 44px; }
  .join-layout, .follow-layout { align-items: start; flex-direction: column; gap: 28px; }
  .join-section { padding-block: 56px; }
  .follow-section { padding-block: 40px; }
  .footer-layout { justify-content: start; }
  .site-footer small { margin-left: auto; }
}
@media (max-width: 480px) {
  .header-inner { padding-inline: 20px; }
  .container { width: calc(100% - 40px); }
  .hero { min-height: 620px; }
  .hero-image { object-position: 58% center; }
  .hero h1 { font-size: clamp(30px, 8.6vw, 36px); letter-spacing: .01em; }
  .hero-content { padding-top: 46px; }
  .eyebrow { font-size: 10px; letter-spacing: .12em; }
  .hero-actions { align-items: start; flex-direction: column; gap: 16px; }
  .hero-bottom { font-size: 10px; }
  .hero-location { display: none; }
  .mobile-break { display: inline; }
  h2, .about-intro h2 { font-size: 25px; }
  .event-date { width: 78px; }
  .event-date span { font-size: 9px; }
  .event-date strong { font-size: 42px; }
  .event-body { padding: 20px 16px; flex-basis: calc(100% - 78px); }
  .event-body h3 { font-size: 17px; }
  .event-meta { gap: 4px 14px; }
  .steps { grid-template-columns: 1fr; gap: 28px; }
  .steps h3 { font-size: 18px; margin-top: 10px; }
  .steps p { max-width: 36ch; }
  .social-links { width: 100%; gap: 12px; }
  .social-links a { flex: 1 1 130px; min-width: 0; }
  .site-footer p { flex-basis: 100%; }
  .site-footer small { margin-left: 0; }
  .repository-link { flex-direction: column; gap: 12px; }
  .repository-meta { width: 100%; flex-direction: row; align-items: center; justify-content: space-between; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}