@import url("https://fonts.googleapis.com/css2?family=M+PLUS+1+Code:wght@400;500;600;700;800&display=swap");

/* 白とエメラルドを基調に、コードエディタのグリッドとシアンを添えます。 */
:root {
  --ink: #102f2a;
  --muted: #506a64;
  --emerald: #20b987;
  --link: #08785b;
  --mint: #ecfaf5;
  --line: #d4e9e2;
  --soft-shadow: 0 4px 18px #102f2a0a;
  --code-font: "M PLUS 1 Code", ui-monospace, "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

body {
  color: var(--ink);
  font-family: var(--code-font);
  background-color: #fff;
  background-image:
    linear-gradient(#20b9870a 1px, transparent 1px),
    linear-gradient(90deg, #20b9870a 1px, transparent 1px);
  background-size: 32px 32px;
}

main { position: relative; isolation: isolate; }
/* 装飾は本文幅の外側に置き、クリックや読み上げの対象にしません。 */
main::before, main::after {
  content: "";
  position: absolute;
  z-index: -1;
  width: 64px;
  height: 88px;
  pointer-events: none;
  background:
    linear-gradient(90deg, var(--emerald) 50%, transparent 50%) 0 0 / 16px 2px,
    linear-gradient(var(--emerald) 50%, transparent 50%) 0 0 / 2px 16px;
  opacity: .25;
}
main::before { top: 400px; left: max(12px, calc(50% - 540px)); }
main::after { top: 1900px; right: max(12px, calc(50% - 540px)); }

.page-header {
  background: radial-gradient(circle at 100% 0, #f1faf6 0 70px, transparent 71px);
}
.section { background: #fff; }
.section > h2 {
  display: flex;
  align-items: baseline;
  gap: 14px;
  text-align: left;
  line-height: 1.5;
}
.section > h2::before {
  content: "";
  flex: 0 0 18px;
  height: 18px;
  border-radius: 4px;
  background: var(--emerald);
}

.event-details, .card, .project-disclosure, .news-list, .social-link, #about > p {
  border: 1px solid var(--line);
  border-left: 4px solid var(--emerald);
  border-radius: 12px;
  background: #fff;
  box-shadow: var(--soft-shadow);
}
.event-details {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 12px 24px;
  padding: 24px;
  text-align: left;
}
.event-details dt, .event-details dt:not(:first-child) {
  margin: 0;
  padding: 6px 16px;
  border-radius: 8px;
  color: var(--link);
  background: var(--mint);
  text-align: center;
}
.event-details dd { margin: 0; }
#about > p { padding: 20px 24px; }

.news-disclosure + .news-disclosure { border-color: var(--line); }
.project-disclosure summary, .news-disclosure summary {
  color: var(--ink);
  background: #fff;
}
.project-disclosure[open] summary { border-color: var(--line); }
.project-disclosure summary:hover, .news-disclosure summary:hover,
.social-link:hover, .sidebar-links a:hover { background: var(--mint); }
.social-link:hover, .sidebar-links a:hover { border-color: var(--emerald); }
.project-disclosure summary::marker, .news-disclosure summary::marker { color: var(--link); }
.project-body { background: #fff; }

.platform, .link-label { color: var(--link); }
.news-date, .map-credit { color: var(--muted); }
.access-map {
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  box-shadow: var(--soft-shadow);
}
.map-image { border: 0; border-radius: 6px; }
.map-credit { padding: 0 8px 4px; }
.slideshow-stage { background: #f3f7f5; }

.menu-toggle {
  color: #fff;
  background: var(--link);
  border-color: var(--link);
  box-shadow: 0 3px 12px #183c341a;
}
.menu-toggle:hover { background: #12553f; }
.sidebar { color: var(--ink); }
.sidebar::backdrop { background: #183c3459; }
.menu-close, .sidebar-links a, .news-controls select,
.slideshow-toggle, .slideshow-arrow {
  color: var(--link);
  border-color: var(--line);
}
.menu-close { background: var(--mint); }
a:focus-visible, button:focus-visible, .news-controls select:focus-visible,
.project-disclosure summary:focus-visible, .news-disclosure summary:focus-visible {
  outline-color: var(--link);
}

@media (max-width: 960px) {
  /* 狭い画面では装飾を控え、本文に重ならないようにします。 */
  main::before, main::after { display: none; }
  body { background-image: none; }
}
@media (max-width: 480px) {
  .section > h2 { gap: 10px; }
  .section > h2::before { flex-basis: 14px; height: 14px; border-radius: 3px; }
  .event-details { grid-template-columns: 1fr; gap: 8px; padding: 18px; }
  .event-details dt { justify-self: start; }
  .event-details dd:not(:last-child) { margin-bottom: 12px; }
  #about > p { padding: 18px; }
}