/* ============================================
   Yamamoto Laboratory — Design System
   Modern academic design with clean aesthetics
   ============================================ */

/* ---------- CSS Variables ---------- */
:root {
  /* Colors — Lime Green Theme */
  --color-primary: #1a2e1a;
  --color-primary-light: #3d6b35;
  --color-primary-dark: #0d1a0d;
  --color-accent: #84cc16;
  --color-accent-light: #a3e635;
  --color-accent-hover: #65a30d;
  --color-bg: #f7faf2;
  --color-bg-white: #ffffff;
  --color-bg-card: #ffffff;
  --color-bg-hero: linear-gradient(
    135deg,
    #0d1a0d 0%,
    #1a3a1a 40%,
    #2d5a27 100%
  );
  --color-text: #1a2e1a;
  --color-text-secondary: #4a6741;
  --color-text-light: #7a9970;
  --color-text-inverse: #f0f7ea;
  --color-border: #d4e5cd;
  --color-border-light: #ecf4e7;
  --color-success: #22c55e;
  --color-warning: #eab308;
  --color-danger: #ef4444;

  /* Typography */
  --font-sans:
    "Inter", "Noto Sans JP", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Layout */
  --max-width: 1200px;
  --header-height: 72px;
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --border-radius-xl: 16px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md:
    0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg:
    0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.03);
  --shadow-xl:
    0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul,
ol {
  list-style: none;
}

/* ---------- Utility Classes ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section {
  padding: var(--space-20) 0;
}

.section-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
  position: relative;
  letter-spacing: -0.02em;
}

.section-title::after {
  content: "";
  display: block;
  width: 64px;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--color-accent),
    var(--color-accent-light)
  );
  border-radius: 2px;
  margin-top: var(--space-3);
}

.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-12);
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.site-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  gap: 12px;
}

.logo-img {
  height: 48px;
  width: auto;
}

.logo-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-logo .lab-name {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.site-logo .university-name {
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  line-height: 1.2;
}

/* Navigation */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.main-nav a {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--border-radius);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--color-primary);
  background: var(--color-border-light);
}

.lang-switch {
  margin-left: var(--space-4);
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
  border-radius: 999px;
  background: transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}

.lang-switch:hover {
  background: var(--color-accent);
  color: #fff;
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  color: var(--color-text);
  border-radius: var(--border-radius);
  transition: background var(--transition-fast), color var(--transition-fast);
  z-index: 1001;
}

.menu-toggle:hover {
  background: var(--color-border-light);
}

.menu-toggle.active {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.menu-toggle svg {
  width: 24px;
  height: 24px;
  display: block;
}

.menu-toggle svg line {
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  transform-origin: center;
}

.menu-toggle.active .line1 {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle.active .line2 {
  opacity: 0;
}

.menu-toggle.active .line3 {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---------- Hero Section ---------- */
.hero {
  background: var(--color-bg-hero);
  color: var(--color-text-inverse);
  padding: var(--space-24) 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -50%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(
    circle,
    rgba(132, 204, 22, 0.12) 0%,
    transparent 70%
  );
  pointer-events: none;
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% {
    transform: translate(0, 0) scale(1);
  }

  100% {
    transform: translate(-40px, -40px) scale(1.15);
  }
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: var(--font-size-5xl);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: var(--space-4);
  letter-spacing: -0.03em;
}

.hero h1 .highlight {
  background: linear-gradient(135deg, var(--color-accent-light), #4ade80);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: var(--font-size-lg);
  color: rgba(255, 255, 255, 0.8);
  max-width: 600px;
  margin-bottom: var(--space-6);
}

/* Hero Slideshow */
.hero-slideshow {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
}

.hero-slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  opacity: 0;
  animation: heroSlide 15s infinite;
}

.hero-slide::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(13, 26, 13, 0.82) 0%,
    rgba(26, 58, 26, 0.72) 40%,
    rgba(45, 90, 39, 0.68) 100%
  );
}

.hero-slide:nth-child(1) {
  animation-delay: 0s;
}

.hero-slide:nth-child(2) {
  animation-delay: 5s;
}

.hero-slide:nth-child(3) {
  animation-delay: 10s;
}

@keyframes heroSlide {
  0% {
    opacity: 0;
    transform: scale(1.05);
  }

  5% {
    opacity: 1;
    transform: scale(1);
  }

  33% {
    opacity: 1;
    transform: scale(1.03);
  }

  38% {
    opacity: 0;
    transform: scale(1.05);
  }

  100% {
    opacity: 0;
  }
}

/* Hero Affiliations */
.hero-affiliations {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
}

.hero-aff-tag {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 500;
  padding: var(--space-1) var(--space-3);
  background: rgba(132, 204, 22, 0.15);
  border: 1px solid rgba(132, 204, 22, 0.3);
  border-radius: 999px;
  color: var(--color-accent-light);
  letter-spacing: 0.01em;
}

.hero-stats {
  display: flex;
  gap: var(--space-10);
  margin-top: var(--space-10);
}

.hero-stat {
  text-align: center;
}

.hero-stat .stat-number {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  display: block;
}

.hero-stat .stat-label {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.7);
}

/* ---------- Card ---------- */
.card {
  background: var(--color-bg-card);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
  padding: var(--space-6);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--color-accent),
    var(--color-accent-light),
    #4ade80
  );
  opacity: 0;
  transition: opacity var(--transition-base);
}

.card:hover {
  box-shadow:
    var(--shadow-lg),
    0 0 0 1px rgba(132, 204, 22, 0.08);
  transform: translateY(-4px);
  border-color: var(--color-accent-light);
}

.card:hover::before {
  opacity: 1;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-6);
}

/* ---------- News Year Filter ---------- */
.news-year-filter {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-6);
  padding: var(--space-2);
  background: var(--color-bg);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
}

.news-year-tab {
  padding: var(--space-2) var(--space-5);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  background: transparent;
  border: none;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.news-year-tab:hover {
  color: var(--color-primary);
  background: var(--color-bg-white);
}

.news-year-tab.active {
  color: var(--color-bg-white);
  background: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

/* ---------- News ---------- */
.news-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.news-item {
  display: flex;
  gap: var(--space-6);
  padding: var(--space-6);
  background: var(--color-bg-card);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  transition: all var(--transition-base);
}

.news-item:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent-light);
  border-left-color: var(--color-accent);
  transform: translateX(4px);
}

.news-date {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  background: linear-gradient(135deg, #f0fdf0, #ecfccb);
  border-radius: var(--border-radius);
  text-align: center;
  border: 1px solid #d9f99d;
}

.news-date .month {
  font-size: var(--font-size-xs);
  font-weight: 700;
  color: var(--color-accent-hover);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.news-date .day {
  font-size: var(--font-size-2xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
}

.news-body h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.news-category {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: 999px;
  background: linear-gradient(135deg, #ecfccb, #d9f99d);
  color: #3f6212;
  margin-bottom: var(--space-2);
  letter-spacing: 0.02em;
}

.news-body p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* News Item Link Wrapper */
.news-item-link {
  text-decoration: none;
  color: inherit;
  display: block;
}

.news-thumb {
  flex-shrink: 0;
  width: 120px;
  height: 80px;
  border-radius: var(--border-radius);
  overflow: hidden;
}

.news-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.news-item-link:hover .news-thumb img {
  transform: scale(1.05);
}

.news-readmore {
  display: inline-block;
  margin-top: var(--space-2);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent-hover);
  transition: color var(--transition-fast);
}

.news-item-link:hover .news-readmore {
  color: var(--color-accent);
}

/* News Detail Page */
.breadcrumb {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.breadcrumb a {
  color: var(--color-accent-hover);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.news-detail {
  max-width: 800px;
  margin: 0 auto;
}

.news-detail-header {
  margin-bottom: var(--space-8);
}

.news-detail-meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.news-detail-date {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.news-detail-title {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.news-detail-image {
  margin-bottom: var(--space-8);
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.news-detail-image img {
  width: 100%;
  height: auto;
  display: block;
}

.news-detail-content {
  font-size: var(--font-size-lg);
  line-height: 1.9;
  color: var(--color-text);
  margin-bottom: var(--space-12);
  padding: var(--space-8);
  background: var(--color-bg-card);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
}

.news-detail-footer {
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
}

/* ---------- Members ---------- */
.member-section {
  margin-bottom: var(--space-12);
}

.member-section h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border);
}

.faculty-card {
  display: flex;
  gap: var(--space-8);
  padding: var(--space-8);
  background: var(--color-bg-card);
  border-radius: var(--border-radius-xl);
  border: 1px solid var(--color-border);
  margin-bottom: var(--space-6);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.collaborator-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

@media (min-width: 992px) {
  .collaborator-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.collaborator-grid .faculty-card {
  padding: var(--space-5);
  gap: var(--space-5);
  margin-bottom: 0;
}

.collaborator-grid .faculty-avatar {
  width: 90px;
  height: 90px;
}

.collaborator-grid .faculty-info h4 {
  font-size: var(--font-size-xl);
}

.faculty-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--color-accent),
    var(--color-accent-light)
  );
}

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

.faculty-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  background: linear-gradient(135deg, #f0fdf0, #ecfccb);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-3xl);
  color: var(--color-text-light);
  border: 3px solid var(--color-border-light);
}

.faculty-avatar img {
  border-radius: 50%;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.faculty-info h4 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}

.faculty-info .role {
  font-size: var(--font-size-sm);
  color: var(--color-accent-hover);
  font-weight: 600;
  margin-bottom: var(--space-4);
}

.faculty-links {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.faculty-links a {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--border-radius);
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-fast);
}

.faculty-links a:hover {
  color: var(--color-accent-hover);
  border-color: var(--color-accent);
  background: #f0fdf0;
}

.student-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: var(--space-4);
}

.student-card {
  padding: var(--space-5);
  background: var(--color-bg-card);
  border-radius: var(--border-radius);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
  position: relative;
  /* overflow: hidden; Removed to allow speech bubble tail */
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.student-avatar {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: var(--space-3);
  border: 2px solid var(--color-border);
}

.student-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* .student-card::before was removed as it relied on overflow:hidden */

.student-card:hover {
  border-color: var(--color-accent-light);
  box-shadow:
    var(--shadow-md),
    0 0 0 2px rgba(132, 204, 22, 0.1);
}

.student-card .name {
  font-weight: 600;
  color: var(--color-primary);
}

.student-card .grade {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* ---------- Research ---------- */
.student-message {
  font-size: 0.85em;
  color: var(--color-text);
  background: #f0fdf0;
  padding: 8px 12px;
  border-radius: 12px;
  position: relative;
  margin-top: 12px;
  border: 1px solid #dcfce7;
  line-height: 1.5;
  text-align: center;
}

.student-message::before {
  content: "";
  position: absolute;
  top: -6px;
  left: 50%;
  transform: translateX(-50%);
  border-width: 0 6px 6px;
  border-style: solid;
  border-color: transparent transparent #dcfce7 transparent;
}

.student-message::after {
  content: "";
  position: absolute;
  top: -4px;
  left: 50%;
  transform: translateX(-50%);
  border-width: 0 6px 6px;
  border-style: solid;
  border-color: transparent transparent #f0fdf0 transparent;
}

.research-card {
  padding: 0;
  overflow: hidden;
}

.research-card .research-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: linear-gradient(
    135deg,
    var(--color-primary),
    var(--color-primary-light),
    var(--color-accent)
  );
  position: relative;
}

.research-card .research-content {
  padding: var(--space-6);
}

.research-card h3 {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.research-card .research-body {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.research-card .research-body p {
  margin-bottom: var(--space-3);
}

/* ---------- Publications ---------- */
.pub-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
  padding: var(--space-2);
  background: var(--color-bg);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
}

.pub-tab {
  padding: var(--space-2) var(--space-5);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  background: transparent;
  border: none;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pub-tab:hover {
  color: var(--color-primary);
  background: var(--color-bg-white);
}

.pub-tab.active {
  color: var(--color-bg-white);
  background: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.pub-year-section {
  margin-bottom: var(--space-10);
}

.pub-year-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.pub-year-title .year-badge {
  background: var(--color-accent);
  color: #fff;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
}

.pub-category {
  margin-bottom: var(--space-8);
}

.pub-category h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
  padding-left: var(--space-4);
  border-left: 3px solid var(--color-accent);
}

.pub-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.pub-item {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--color-bg-card);
  border-radius: var(--border-radius);
  border: 1px solid var(--color-border);
  align-items: baseline;
  transition: border-color var(--transition-fast);
}

.pub-item:hover {
  border-color: var(--color-accent-light);
}

.pub-number {
  font-weight: 700;
  color: var(--color-accent);
  font-size: var(--font-size-sm);
  flex-shrink: 0;
  min-width: 32px;
}

.pub-citation {
  font-size: var(--font-size-sm);
  line-height: 1.7;
  color: var(--color-text);
  flex: 1;
}

.pub-doi {
  margin-left: var(--space-2);
}

.pub-doi a {
  font-size: var(--font-size-xs);
  color: var(--color-accent);
  background: #f0fdf0;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--border-radius);
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.pub-doi a:hover {
  background: var(--color-accent);
  color: #fff;
}

/* Grants section */
.grants-section {
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 2px solid var(--color-border);
}

/* ---------- Links Page ---------- */
.links-category {
  margin-bottom: var(--space-12);
}

.links-category-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.links-category-icon {
  font-size: var(--font-size-2xl);
}

.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-4);
}

.link-card {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-6);
  background: var(--color-bg-card);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-border);
  text-decoration: none;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.link-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-accent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.link-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.link-card:hover::before {
  opacity: 1;
}

.link-card-body {
  flex: 1;
  min-width: 0;
}

.link-card-body h4 {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
  line-height: 1.4;
}

.link-card-body p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.link-card-arrow {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.link-card:hover .link-card-arrow {
  color: var(--color-accent);
  transform: translate(2px, -2px);
}

/* ---------- Assignment ---------- */
.assignment-content {
  background: var(--color-bg-card);
  border-radius: var(--border-radius-xl);
  border: 1px solid var(--color-border);
  padding: var(--space-10);
  line-height: 1.8;
}

.assignment-content h2,
.assignment-content h3 {
  color: var(--color-primary);
  margin: var(--space-6) 0 var(--space-3);
}

.assignment-content p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

.assignment-content ul {
  list-style: disc;
  margin-left: var(--space-8);
  margin-bottom: var(--space-6);
  color: var(--color-text-secondary);
}

.assignment-content li {
  margin-bottom: var(--space-2);
}

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
}

.contact-info {
  background: var(--color-bg-card);
  border-radius: var(--border-radius-xl);
  border: 1px solid var(--color-border);
  padding: var(--space-8);
}

.contact-info h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
}

.contact-detail {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
}

.contact-detail .icon {
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius);
  background: #f0fdf0;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--color-accent);
}

.contact-detail .detail-text {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.contact-detail .detail-text strong {
  display: block;
  color: var(--color-text);
  font-size: var(--font-size-base);
  margin-bottom: var(--space-1);
}

.contact-form {
  background: var(--color-bg-card);
  border-radius: var(--border-radius-xl);
  border: 1px solid var(--color-border);
  padding: var(--space-8);
}

.form-group {
  margin-bottom: var(--space-5);
}

.form-group label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-size-base);
  font-family: var(--font-sans);
  border: 1.5px solid var(--color-border);
  border-radius: var(--border-radius);
  background: var(--color-bg-white);
  color: var(--color-text);
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(132, 204, 22, 0.15);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--font-size-sm);
  font-weight: 600;
  font-family: var(--font-sans);
  border-radius: var(--border-radius);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  position: relative;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--color-accent),
    var(--color-accent-hover)
  );
  color: #fff;
  box-shadow: 0 2px 8px rgba(132, 204, 22, 0.25);
}

.btn-primary:hover {
  background: linear-gradient(
    135deg,
    var(--color-accent-light),
    var(--color-accent)
  );
  box-shadow: 0 4px 16px rgba(132, 204, 22, 0.35);
  transform: translateY(-2px);
  color: #fff;
}

.btn-secondary {
  background: var(--color-bg);
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent-hover);
  background: #f0fdf0;
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-base);
  border-radius: var(--border-radius-lg);
}

/* ---------- Footer ---------- */
.site-footer {
  background: linear-gradient(
    180deg,
    var(--color-primary-dark) 0%,
    #060d06 100%
  );
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-16) 0 var(--space-8);
  position: relative;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--color-accent),
    var(--color-accent-light),
    var(--color-accent)
  );
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-info h3 {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-4);
}

.footer-info p {
  font-size: var(--font-size-sm);
  line-height: 1.8;
  margin-bottom: var(--space-2);
}

.footer-links h4 {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer-links a {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  transition: all var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-accent-light);
  padding-left: var(--space-1);
}

.footer-bottom {
  padding-top: var(--space-8);
  border-top: 1px solid rgba(132, 204, 22, 0.15);
  text-align: center;
  font-size: var(--font-size-xs);
  color: rgba(255, 255, 255, 0.4);
}

/* ---------- 404 ---------- */
.page-404 {
  text-align: center;
  padding: var(--space-24) 0;
}

.page-404 h1 {
  font-size: 6rem;
  font-weight: 800;
  color: var(--color-border);
  line-height: 1;
}

.page-404 p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin: var(--space-4) 0 var(--space-8);
}

/* ---------- Flash Messages ---------- */
.flash {
  padding: var(--space-4) var(--space-6);
  border-radius: var(--border-radius);
  margin-bottom: var(--space-6);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.flash-success {
  background: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.flash-error {
  background: #fef2f2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .menu-toggle {
    display: block;
  }

  .main-nav {
    display: flex;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    height: calc(100vh - var(--header-height));
    height: calc(100dvh - var(--header-height));
    background: linear-gradient(
      180deg,
      #ffffff 0%,
      #f7faf2 100%
    );
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    padding: var(--space-8) var(--space-6);
    gap: 0;
    transform: translateX(100%);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 999;
    overflow-y: auto;
  }

  .main-nav.open {
    transform: translateX(0);
  }

  /* スタッガーアニメーション: 各リンクがふわっと現れる */
  .main-nav a {
    font-size: var(--font-size-base);
    font-weight: 500;
    letter-spacing: 0.02em;
    padding: var(--space-3) var(--space-5);
    width: 100%;
    background: transparent;
    border: none;
    border-radius: var(--border-radius-lg);
    text-align: left;
    color: var(--color-text-secondary);
    position: relative;
    opacity: 0;
    transform: translateY(12px);
    transition:
      opacity 0.4s cubic-bezier(0.22, 1, 0.36, 1),
      transform 0.4s cubic-bezier(0.22, 1, 0.36, 1),
      background var(--transition-fast),
      color var(--transition-fast);
  }

  .main-nav a::after {
    content: "";
    position: absolute;
    left: var(--space-5);
    right: var(--space-5);
    bottom: 0;
    height: 1px;
    background: var(--color-border-light);
  }

  .main-nav a:last-child::after {
    display: none;
  }

  .main-nav a:hover {
    background: rgba(132, 204, 22, 0.08);
    color: var(--color-primary);
  }

  .main-nav a.active {
    color: var(--color-accent-hover);
    font-weight: 600;
    background: rgba(132, 204, 22, 0.06);
  }

  .main-nav a.active::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    border-radius: 0 3px 3px 0;
    background: var(--color-accent);
  }

  /* メニューオープン時に各項目を順次表示 */
  .main-nav.open a {
    opacity: 1;
    transform: translateY(0);
  }

  .main-nav.open a:nth-child(1) { transition-delay: 0.06s; }
  .main-nav.open a:nth-child(2) { transition-delay: 0.10s; }
  .main-nav.open a:nth-child(3) { transition-delay: 0.14s; }
  .main-nav.open a:nth-child(4) { transition-delay: 0.18s; }
  .main-nav.open a:nth-child(5) { transition-delay: 0.22s; }
  .main-nav.open a:nth-child(6) { transition-delay: 0.26s; }
  .main-nav.open a:nth-child(7) { transition-delay: 0.30s; }
  .main-nav.open a:nth-child(8) { transition-delay: 0.34s; }

  .lang-switch {
    margin: var(--space-4) auto 0 !important;
    align-self: center;
    padding: var(--space-2) var(--space-5) !important;
    font-size: var(--font-size-sm) !important;
    border: 1.5px solid var(--color-accent) !important;
    border-radius: 999px !important;
    background: transparent !important;
    color: var(--color-accent) !important;
    opacity: 0;
    transform: translateY(12px);
  }

  .lang-switch::after {
    display: none !important;
  }

  .main-nav.open .lang-switch {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.36s;
  }

  .hero h1 {
    font-size: var(--font-size-3xl);
  }

  .hero-stats {
    flex-wrap: wrap;
    gap: var(--space-6);
  }

  .section {
    padding: var(--space-12) 0;
  }

  .section-title {
    font-size: var(--font-size-2xl);
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .faculty-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .faculty-links {
    justify-content: center;
  }

  .news-item {
    flex-direction: column;
    gap: var(--space-3);
  }

  .news-date {
    flex-direction: row;
    width: auto;
    height: auto;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .pub-item {
    flex-direction: column;
    gap: var(--space-1);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-4);
  }

  .hero {
    padding: var(--space-16) 0;
  }

  .hero h1 {
    font-size: var(--font-size-2xl);
  }

  .student-grid {
    grid-template-columns: 1fr;
  }
}

/* ---------- Animations ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-in {
  animation: fadeInUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) forwards;
  opacity: 0;
}

.animate-in:nth-child(1) {
  animation-delay: 0.05s;
}

.animate-in:nth-child(2) {
  animation-delay: 0.1s;
}

.animate-in:nth-child(3) {
  animation-delay: 0.15s;
}

.animate-in:nth-child(4) {
  animation-delay: 0.2s;
}

.animate-in:nth-child(5) {
  animation-delay: 0.25s;
}

.animate-in:nth-child(6) {
  animation-delay: 0.3s;
}

.animate-in:nth-child(7) {
  animation-delay: 0.35s;
}

.animate-in:nth-child(8) {
  animation-delay: 0.4s;
}