:root {
  --main: #e67e22;
  --main-dark: #ca6f1e;
  --accent: #f39c12;
  --gold: #ffd27f;
  --bg: #fff8f2;
  --text: #2f2f2f;
  --muted: #666666;
  --white: #ffffff;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Inter", Arial, Helvetica, sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
}
a { color: inherit; }
img { max-width: 100%; }

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 20px 6vw;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(230, 126, 34, 0);
  backdrop-filter: blur(0);
  z-index: 30;
  transition: background 0.35s ease, backdrop-filter 0.35s ease, padding 0.35s ease, box-shadow 0.35s ease;
}
.site-header.scrolled,
.site-header.menu-open {
  background: rgba(230, 126, 34, 0.94);
  backdrop-filter: blur(10px);
  padding: 14px 6vw;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}
.logo {
  color: var(--white);
  text-decoration: none;
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: 0.04em;
  z-index: 35;
}
.site-nav {
  display: flex;
  gap: 26px;
  align-items: center;
}
.site-nav a {
  color: var(--white);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
}
.site-nav a:hover { color: var(--gold); }

/* Hamburger */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 40;
  padding: 8px;
}
.menu-toggle span {
  width: 26px;
  height: 2px;
  background: var(--white);
  transition: 0.3s ease;
}
.menu-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.menu-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.42);
  opacity: 0;
  pointer-events: none;
  transition: 0.3s ease;
  z-index: 20;
}
.menu-overlay.active {
  opacity: 1;
  pointer-events: auto;
}
body.no-scroll { overflow: hidden; }

/* Home hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: grid;
  place-items: center;
  text-align: center;
  color: var(--white);
  overflow: hidden;
}
.hero-slider,
.slide,
.hero-overlay {
  position: absolute;
  inset: 0;
}
.slide {
  background-size: cover;
  background-position: center;
  opacity: 0;
  transform: scale(1);
  animation: fadeSlide 18s infinite;
}
.slide-1 { background-image: url("../images/morioka-1.jpg"); animation-delay: 0s; }
.slide-2 { background-image: url("../images/morioka-2.jpg"); animation-delay: 6s; }
.slide-3 { background-image: url("../images/morioka-3.jpg"); animation-delay: 12s; }
@keyframes fadeSlide {
  0% { opacity: 0; transform: scale(1); }
  8% { opacity: 1; }
  33% { opacity: 1; transform: scale(1.08); }
  43% { opacity: 0; transform: scale(1.08); }
  100% { opacity: 0; transform: scale(1); }
}
.hero-overlay {
  background:
    linear-gradient(to bottom, rgba(0,0,0,0.45), rgba(0,0,0,0.55)),
    linear-gradient(rgba(230,126,34,0.18), rgba(230,126,34,0.18));
  z-index: 1;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  opacity: 0.12;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(255,255,255,0.35) 0 1px, transparent 1px),
    radial-gradient(circle at 70% 60%, rgba(255,255,255,0.25) 0 1px, transparent 1px),
    radial-gradient(circle at 40% 80%, rgba(255,255,255,0.18) 0 1px, transparent 1px);
  background-size: 120px 120px, 180px 180px, 240px 240px;
}
.hero-content {
  position: relative;
  z-index: 3;
  padding: 120px 24px 80px;
  max-width: 900px;
  text-shadow: 0 4px 18px rgba(0, 0, 0, 0.55);
}
.eyebrow {
  margin: 0 0 14px;
  color: var(--gold);
  letter-spacing: 0.2em;
  font-size: 0.85rem;
  text-transform: uppercase;
  font-weight: 800;
}
.eyebrow.dark { color: var(--main); text-shadow: none; }
h1 {
  font-family: Oswald;
  font-size: clamp(2rem, 10vw, 4rem);
  line-height: 1.2;
  margin: 0;
}
.date {
  font-family: Oswald;
  font-size: clamp(1.5rem, 3vw, 2.5rem);
  margin: 28px 0 6px;
  font-weight: 800;
}

.description { font-family: Oswald; font-weight: 200; margin: 4px 0; font-size: 1.1rem; }
.date-venue-president {
  font-family: Oswald;
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: .2rem 0 0 0;
  padding: 0;
  font-weight: 600;
}

.venue, .president { margin: 4px 0; font-size: 1.1rem; }
.hero-buttons {
  margin-top: 34px;
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}
.button {
  display: inline-block;
  padding: 12px 26px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 800;
  transition: 0.25s ease;
}
.button.primary { background: var(--white); color: var(--main); }
.button.primary:hover { background: #fff2e6; transform: translateY(-2px); }
.button.secondary { border: 2px solid var(--white); color: var(--white); }
.button.secondary:hover { background: var(--white); color: var(--main); }
.button.large { background: #fff2e6; padding: 16px 32px; font-size: 1.1rem; }
.button.large:hover { background: #FFAE68; color: var(--white); }
.button.large2 { background: var(--white); padding: 16px 32px; font-size: 1.1rem; }
.button.large2:hover { background: #fff2e6; color: var(--main); }

/* Page hero */
.page-hero {
  position: relative;
  height: 55vh;
  min-height: 420px;
  display: flex;
  align-items: center;
  color: var(--white);
  overflow: hidden;
  background-size: cover;
  background-position: center;
}
.about-hero { background-image: url("../images/morioka-2.jpg"); }
.venue-hero { background-image: url("../images/aiina.jpg"); }
.page-hero-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(rgba(0,0,0,0.45), rgba(0,0,0,0.55)),
    rgba(230,126,34,0.12);
  z-index: 1;
}
.page-hero-content {
  position: relative;
  z-index: 2;
  max-width: 900px;
  margin: 0 auto;
  padding: 120px 24px 60px;
  text-shadow: 0 4px 18px rgba(0, 0, 0, 0.6);
}
.page-hero-content h1 {
  font-size: clamp(3rem, 6vw, 5rem);
  margin-bottom: 20px;
}
.page-lead {
  font-size: 1.1rem;
  max-width: 700px;
  margin: 0;
}

/* Layout */
.section { padding: 90px 6vw; }
.light { background: var(--bg); }
.container { max-width: 1080px; margin: 0 auto; }
.two-column {
  display: grid;
  grid-template-columns: 0.9fr 1.4fr;
  gap: 48px;
  align-items: start;
}
.section-heading { margin-bottom: 32px; }
.section-heading.center { text-align: center; }
h2 {
  margin: 0 0 30px;
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--main);
  line-height: 1.2;
}
h3 { margin-top: 40px; color: var(--main); }
ul { margin: 15px 0 25px; padding-left: 20px; }
.content-block p { margin-top: 0; }
.signature { margin-top: 28px; font-weight: 700; }

/* News */
.news-list {
  background: var(--white);
  border-radius: 16px;
  box-shadow: 0 8px 25px rgba(0,0,0,0.08);
  overflow: hidden;
}
.news-item {
  display: grid;
  grid-template-columns: 20px 160px 1fr;
  gap: 16px;
  padding: 20px 24px;
  border-bottom: 1px solid #eee;
  align-items: start;
}
.news-item::before {
  content: "●";
  color: var(--main);
  font-size: 0.8rem;
  margin-top: 0.35em;
}
.news-item:last-child { border-bottom: none; }
.news-item time { color: var(--main); font-weight: 800; }
.news-item p { margin: 0; }

/* About */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 20px;
}
.info-card {
  background: var(--bg);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
}
.info-label {
  display: block;
  color: var(--main);
  font-weight: 800;
  font-size: 0.85rem;
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* Program */
.program-tabs { display: flex; gap: 10px; margin-bottom: 30px; flex-wrap: wrap; }
.tab {
  padding: 10px 18px;
  border-radius: 999px;
  background: #eeeeee;
  border: none;
  cursor: pointer;
  font-weight: 800;
  color: var(--text);
}
.tab.active { background: var(--main); color: var(--white); }
.program-day { display: none; }
.program-day.active { display: block; }
.program-item {
  display: grid;
  grid-template-columns: 100px 1fr;
  padding: 18px 0;
  border-bottom: 1px solid #eeeeee;
}
.program-item p { margin: 4px 0 0; color: var(--muted); }
.time { font-weight: 800; color: var(--main); }

/* Abstract */
.abstract-list li { margin-bottom: 8px; }
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}
.topics-grid div {
  background: var(--bg);
  padding: 24px;
  border-radius: 14px;
  text-align: center;
  font-weight: 800;
}

/* Registration */
.fee-table { overflow-x: auto; }
.fee-table table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  margin-top: 20px;
  background: var(--white);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 8px 25px rgba(0,0,0,0.08);
}
.fee-table th { background: var(--main); color: var(--white); padding: 14px; text-align: left; }
.fee-table td { padding: 14px; border-bottom: 1px solid #eeeeee; }
.fee-table tr:nth-child(even) { background: #fafafa; }
.cta-center { text-align: center; margin-top: 30px; }

/* Venue */
.venue-photo img {
  width: 100%;
  display: block;
  border-radius: 22px;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.16);
}
.access-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}
.access-card {
  background: var(--white);
  padding: 28px;
  border-radius: 18px;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.08);
}
.access-card h3 { margin-top: 0; }
.map-box {
  overflow: hidden;
  border-radius: 22px;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.14);
}

/* Footer */
.site-footer {
  background: var(--main);
  color: var(--white);
  text-align: center;
  padding: 28px 6vw;
  font-size: 0.9rem;
}
.site-footer p { margin: 0; }

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border: none;
  border-radius: 50%;
  background: var(--main);
  color: var(--white);
  font-size: 1.4rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.18);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: 0.3s ease;
  z-index: 30;
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--main-dark);
  transform: translateY(-3px);
}

@media (max-width: 768px) {
  .site-header { padding: 16px 20px; }
  .site-header.scrolled,
  .site-header.menu-open { padding: 14px 20px; }
  .menu-toggle { display: flex; }
  .site-nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: min(78vw, 300px);
    height: 100vh;
    background: var(--main);
    flex-direction: column;
    align-items: flex-start;
    padding: 100px 30px;
    gap: 20px;
    transition: right 0.35s ease;
    z-index: 25;
    box-shadow: -12px 0 30px rgba(0,0,0,0.18);
  }
  .site-nav.open { right: 0; }
  .site-nav a { font-size: 1.2rem; }
  .hero-content { padding: 110px 24px 70px; }
  .hero-buttons { flex-direction: column; align-items: center; }
  .page-hero { min-height: 380px; }
  .section { padding: 64px 24px; }
  .two-column { grid-template-columns: 1fr; gap: 24px; }
  .news-item { grid-template-columns: 20px 1fr; }
  .news-item time,
  .news-item p { grid-column: 2; }
  .program-item { grid-template-columns: 1fr; gap: 4px; }
  .info-grid { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
  .back-to-top {
    right: 18px;
    bottom: 18px;
    width: 44px;
    height: 44px;
    font-size: 1.2rem;
  }
}