/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #991b1b;
  --primary-dark: #7f1d1d;
  --primary-light: #fee2e2;
  --accent: #d97706;
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
  --radius: 12px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Noto Sans JP', 'Montserrat', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.8;
  overflow-x: hidden;
}

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

ul { list-style: none; }

img { max-width: 100%; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Navbar ===== */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: var(--transition);
}

#navbar.scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  padding: 10px 0;
}

.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  font-size: 1.5rem;
  color: #fff;
  transition: var(--transition);
}

#navbar.scrolled .nav-logo {
  color: var(--primary);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: rgba(255,255,255,0.85);
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}

.nav-links a:hover::after {
  width: 100%;
}

#navbar.scrolled .nav-links a {
  color: var(--text);
}

.nav-cta {
  background: var(--accent) !important;
  color: #fff !important;
  padding: 8px 20px;
  border-radius: 100px;
}

.nav-cta::after { display: none !important; }

.nav-cta:hover {
  background: #b45309 !important;
}

#navbar.scrolled .nav-cta {
  color: #fff !important;
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: var(--transition);
}

#navbar.scrolled .nav-toggle span {
  background: var(--text);
}

/* ===== Hero ===== */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #0f172a 0%, #3b0a0a 50%, #0f172a 100%);
  overflow: hidden;
}

#hero-video {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  object-fit: cover;
  pointer-events: none;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 0 24px;
}

.hero-subtitle {
  font-family: 'Montserrat', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-bottom: 16px;
  animation: fadeUp 0.8s 0.3s both;
}

.hero-title {
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 700;
  color: #fff;
  margin-bottom: 20px;
  animation: fadeUp 0.8s 0.5s both;
}

.hero-description {
  font-size: 1.15rem;
  color: rgba(255,255,255,0.7);
  margin-bottom: 36px;
  animation: fadeUp 0.8s 0.7s both;
}

.hero-btn {
  display: inline-block;
  padding: 14px 40px;
  border: 2px solid var(--accent);
  color: var(--accent);
  border-radius: 100px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  animation: fadeUp 0.8s 0.9s both;
}

.hero-btn:hover {
  background: var(--accent);
  color: #fff;
}

.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255,255,255,0.4);
  font-size: 0.75rem;
  letter-spacing: 2px;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, rgba(255,255,255,0.4), transparent);
  animation: scrollPulse 2s infinite;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

/* ===== Section Common ===== */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 4px;
}

.section-subtitle {
  font-family: 'Montserrat', sans-serif;
  text-align: center;
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 48px;
}

/* ===== Animate ===== */
[data-animate] {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate].visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== About ===== */
.about-text {
  column-count: 2;
  column-gap: 40px;
}

.about-text p {
  color: var(--text-light);
  margin-bottom: 16px;
  font-size: 0.95rem;
}

/* ===== Research ===== */
.research-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.research-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.research-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transform: scaleX(0);
  transition: var(--transition);
}

.research-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.research-card:hover::before {
  transform: scaleX(1);
}

.research-icon {
  width: 56px;
  height: 56px;
  color: var(--primary);
  margin-bottom: 20px;
}

.research-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
}

.research-card p {
  color: var(--text-light);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ===== Members ===== */
.members-category {
  margin-bottom: 48px;
}

.members-category-title {
  font-size: 1.2rem;
  color: var(--primary);
  margin-bottom: 20px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary-light);
}

.members-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.members-grid > .member-card:only-child {
  grid-column: 1 / -1;
  justify-self: center;
  max-width: 340px;
  width: 100%;
}

.member-card {
  background: var(--bg-alt);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: var(--transition);
  width: 100%;
  box-sizing: border-box;
}

.member-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.member-avatar {
  width: 80px;
  height: 80px;
  margin: 0 auto 16px;
  border-radius: 50%;
  overflow: hidden;
  background: #e2e8f0;
}

.member-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}

.member-card h4 {
  font-size: 1.05rem;
  margin-bottom: 4px;
}

.member-role {
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.member-field {
  color: var(--text-light);
  font-size: 0.8rem;
}

.members-grid-small {
  grid-template-columns: repeat(3, 1fr);
  grid-auto-rows: 1fr;
}

.member-card-small {
  background: var(--bg-alt);
  border-radius: var(--radius);
  padding: 20px 24px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: center;
  width: 100%;
  box-sizing: border-box;
}

.member-card-small:hover {
  box-shadow: var(--shadow);
}

.member-card-small h4 {
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.member-card-small p {
  color: var(--text-light);
  font-size: 0.82rem;
}

/* ===== Publications ===== */
.pub-filters {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 36px;
}

.pub-filter {
  padding: 8px 24px;
  border: 1px solid var(--border);
  background: var(--bg);
  border-radius: 100px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.pub-filter.active,
.pub-filter:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.pub-list {
  max-width: 800px;
  margin: 0 auto;
}

.pub-item {
  display: flex;
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.pub-item.hidden {
  display: none;
}

.pub-year {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  color: var(--text-light);
  font-size: 0.9rem;
  flex-shrink: 0;
  padding-top: 4px;
}

.pub-content h4 {
  font-size: 0.95rem;
  margin-bottom: 4px;
  line-height: 1.5;
}

.pub-content p {
  color: var(--text-light);
  font-size: 0.85rem;
}

.pub-tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 100px;
  font-size: 0.7rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.pub-tag.conference { background: #dbeafe; color: #1d4ed8; }
.pub-tag.journal { background: #d1fae5; color: #065f46; }
.pub-tag.award { background: #ede9fe; color: #5b21b6; }

/* ===== Access ===== */
.access-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.access-item {
  margin-bottom: 28px;
}

.access-item h4 {
  font-size: 1rem;
  color: var(--primary);
  margin-bottom: 8px;
}

.access-item p {
  color: var(--text-light);
  font-size: 0.9rem;
}

.access-map iframe {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: block;
  width: 100%;
  height: 400px;
}

/* ===== Contact ===== */
.contact-form {
  max-width: 640px;
  margin: 0 auto;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 6px;
}

.required {
  color: #ef4444;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.9rem;
  transition: var(--transition);
  background: var(--bg);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.submit-btn {
  display: block;
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.submit-btn:hover {
  background: var(--primary-dark);
}

.form-status {
  text-align: center;
  margin-top: 16px;
  font-size: 0.9rem;
}

.form-status.success { color: #059669; }
.form-status.error { color: #ef4444; }

.field-error {
  display: block;
  color: #ef4444;
  font-size: 0.8rem;
  margin-top: 4px;
}

/* ===== Footer ===== */
footer {
  background: #1a0505;
  color: rgba(255,255,255,0.7);
  padding: 60px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 40px;
}

.footer-about h3 {
  font-family: 'Montserrat', sans-serif;
  font-size: 1.5rem;
  color: #fff;
  margin-bottom: 8px;
}

.footer-links h4 {
  color: #fff;
  margin-bottom: 16px;
  font-size: 0.9rem;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  font-size: 0.85rem;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
  text-align: center;
  font-size: 0.8rem;
}

.mobile-br { display: none; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .mobile-br { display: inline; }
  .nav-toggle { display: flex; }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: #fff;
    flex-direction: column;
    padding: 80px 32px 32px;
    gap: 20px;
    transition: var(--transition);
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open { right: 0; }
  .nav-links a { color: var(--text) !important; font-size: 1rem; }

  .about-text {
    column-count: 1;
  }

  .access-grid,
  .form-row {
    grid-template-columns: 1fr;
  }

  .research-grid,
  .members-grid,
  .members-grid-small {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .pub-item { flex-direction: column; gap: 8px; }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .research-grid { grid-template-columns: repeat(2, 1fr); }
  .members-grid { grid-template-columns: repeat(2, 1fr); }
}