:root {
  --bg:#efffff;
  --hero-fg:#fffafa;
  --accent:#ff4500;
  --box-bg:#ffffff;
  --box-border:#ddd;
}

html { box-sizing: border-box; }
*, *::before, *::after { box-sizing: inherit; }

body {
  margin: 0;
  font-size: 18px;
  line-height: 1.7;
  background: var(--bg);
  color: #111;
  -webkit-text-size-adjust: 100%;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 16px;
}

h1 {
  font-size: clamp(26px, 4vw, 40px);
  margin: 0 0 12px;
}
h2 {
  font-size: clamp(20px, 2.8vw, 26px);
  margin-top: 32px;
}

a {
  transition: text-decoration-color .2s ease, text-underline-offset .2s ease, color .2s ease;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  color: #0645ad;
}
a:visited { color: #0645ad; }
a:hover {
  color: #0b4fb3 !important;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}
a:focus { outline: 3px solid #f89174; outline-offset: 2px; }

hr { margin: 32px 0; }

.section-box {
  background: var(--box-bg);
  border: 1px solid var(--box-border);
  border-radius: 8px;
  padding: 16px;
  margin: 16px 0;
  box-shadow: 0 2px 4px rgba(0,0,0,.05);
}

.hero {
  position: relative;
  min-height: 260px;
  padding: clamp(24px, 5vw, 48px) 0;
  color: var(--hero-fg);
  background: url(./index.jpg) center / cover no-repeat;
  text-align: center;
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background: rgba(0,0,0,.35);
}
.hero > * { position: relative; z-index: 1; }

.hero-block { 
  margin-bottom: 32px;
}
.hero-block.ja h1 {
  font-size: clamp(26px, 4vw, 40px);
  margin: 0;
  color: var(--hero-fg);
}

.hero-block.ja .info-line,
.hero-block.en .info-line {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 6px;
}

.hero-block.ja .info-line span {
  font-size: clamp(18px, 3vw, 26px);
  font-weight: 600;
  color: var(--hero-fg);
  text-shadow: 1px 1px 3px rgba(0,0,0,0.6);
}

.hero-block.en .sub {
  display: block;
  font-size: clamp(18px, 3vw, 28px);
  color: var(--hero-fg);
}
.hero-block.en .info-line span {
  font-size: clamp(16px, 2.5vw, 24px);
  color: var(--hero-fg);
}

.hero-block.ja .info-line span.date-ja::after,
.hero-block.en .info-line span.date-en::after {
  content: " / ";
  margin: 0 0.3em;
  color: var(--hero-fg);
}

.hero .credit {
  text-align: right;
  opacity: .9;
  font-size: 0.9rem;
}

img, iframe {
  max-width: 100%;
  height: auto;
  display: block;
}
.figure-responsive { margin: 0; }
.embed-16x9 {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
}
.embed-16x9 > iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.note-accent {
  color: var(--accent);
  font-weight: 700;
}
.highlight-blue {
  font-size: clamp(18px, 2.8vw, 28px);
  color: #0b4fb3;
  font-weight: bold;
}

.label {
  font-weight: bold;
  color: #000;
}

.committee-list {
  list-style: none;
  padding-left: 0;
  margin: 0;
}
.committee-list li {
  padding: 6px 0;
  border-bottom: 1px solid #eee;
  font-size: 1rem;
  line-height: 1.6;
}
.committee-list li:last-child { border-bottom: none; }

@media (min-width: 768px) {
  .committee-list li { padding: 8px 0; }
}

.footer-links { margin-top: 8px; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
}

.skip-link:focus {
  left: 8px;
  top: 8px;
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 999;
  background: rgba(255,255,255,.9);
  backdrop-filter: saturate(120%) blur(6px);
  border-bottom: 1px solid var(--box-border);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
}
.brand {
  font-weight: 800;
  text-decoration: none;
  font-size: clamp(18px, 2.6vw, 22px);
  color: #111;
}
.brand:visited { color: #111; }

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--box-border);
  border-radius: 8px;
  background: var(--box-bg);
  cursor: pointer;
}
.nav-toggle:focus { outline: 3px solid #f89174; outline-offset: 2px; }
.nav-toggle-bar {
  width: 22px; height: 2px;
  background: #111; border-radius: 2px;
  transition: transform .25s ease, opacity .25s ease;
}

.nav-menu {
  position: absolute;
  left: 0; right: 0; top: 56px;
  background: #fff;
  border-bottom: 1px solid var(--box-border);
  margin: 0; padding: 8px 0;
  list-style: none;
  display: none;
}
.nav-menu li { margin: 0; }
.nav-menu a {
  display: block;
  padding: 12px 16px;
  text-decoration: none;
  color: #111;
}
.nav-menu a:hover, .nav-menu a:focus {
  background: var(--bg);
}

.site-nav.open .nav-menu { display: block; }
.site-nav.open .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.site-nav.open .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}
.site-nav.open .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .nav-menu {
    position: static;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 0;
    border: 0;
    background: transparent;
  }
  .nav-menu a {
    padding: 10px 12px;
    border-radius: 8px;
  }
  .nav-menu a:hover, .nav-menu a:focus {
    background: rgba(0,0,0,.04);
  }
}

.nav-menu a[aria-current="page"],
.nav-menu a.is-active {
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
}

.hero { scroll-margin-top: 70px; }
section[id] { scroll-margin-top: 80px; }

.btn {
  display: inline-block;
  padding: 12px 18px;
  border-radius: 10px;
  font-weight: 700;
  text-decoration: none;
  border: 2px solid transparent;
  transition: transform .05s ease, box-shadow .2s ease, background-color .2s ease, color .2s ease;
  line-height: 1.2;
  cursor: pointer;
}
.btn:focus { outline: 3px solid #f89174; outline-offset: 2px; }
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 6px rgba(0,0,0,.12);
}
.btn-primary:hover { filter: brightness(1.05); }
.btn-primary:visited { color: #fff; }

.btn-row { display: flex; flex-wrap: wrap; gap: 10px; }

@media (min-width: 768px) {
  .nav-menu {
    gap: 16px;
  }
  .nav-menu a {
    font-size: 18px;
  }
}

main h1 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 800;
  margin-top: 24px;
  margin-bottom: 16px;
  color: #111;
  border-left: 6px solid var(--accent);
  padding-left: 12px;
}

h2[id] {
  scroll-margin-top: 100px;
}