/* ========================================
   Affective Information Media Lab — Site Styles
   ======================================== */

/* --- CSS Custom Properties --- */
:root {
  --color-bg: #fafafa;
  --color-bg-alt: #f0f0f0;
  --color-text: #1a1a1a;
  --color-text-secondary: #555;
  --color-accent: #2d5a7b;
  --color-accent-light: #3a7ca5;
  --color-border: #ddd;
  --color-card-bg: #fff;
  --color-card-shadow: rgba(0, 0, 0, 0.06);
  --color-hero-overlay: rgba(255, 255, 255, 0.85);
  --font-heading: 'Inter', 'Noto Sans JP', sans-serif;
  --font-body: 'Inter', 'Noto Sans JP', sans-serif;
  --max-width: 1100px;
  --nav-height: 60px;
  --section-padding: 5rem 1.5rem;
  --transition: 0.3s ease;
}

[data-theme="dark"] {
  --color-bg: #111;
  --color-bg-alt: #1a1a1a;
  --color-text: #e8e8e8;
  --color-text-secondary: #aaa;
  --color-accent: #5a9ec5;
  --color-accent-light: #7ab8db;
  --color-border: #333;
  --color-card-bg: #1e1e1e;
  --color-card-shadow: rgba(0, 0, 0, 0.3);
  --color-hero-overlay: rgba(17, 17, 17, 0.85);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-body);
  font-size: 1.1rem;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

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

/* --- Navigation --- */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: background var(--transition), box-shadow var(--transition);
}

.site-nav.scrolled {
  box-shadow: 0 2px 12px var(--color-card-shadow);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
}

.nav-logo {
  height: 40px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-icon {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 0.4rem 0.6rem;
  cursor: pointer;
  color: var(--color-text-secondary);
  font-size: 0.8rem;
  transition: all var(--transition);
}

.btn-icon:hover {
  background: var(--color-bg-alt);
  color: var(--color-text);
}

.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  transition: all var(--transition);
}

/* --- Mobile Nav --- */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    flex-direction: column;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--color-border);
    gap: 0.5rem;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: 0.6rem 0;
    display: block;
  }

  .hamburger {
    display: block;
  }
}

/* --- Section Base --- */
.section {
  padding: var(--section-padding);
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  margin-bottom: 2.5rem;
}

.subsection-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 3rem;
  margin-bottom: 1.5rem;
  color: var(--color-text);
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-border);
}

/* --- Research Agenda --- */
.research-agenda {
  margin-bottom: 3rem;
  padding: 2rem;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
}

.agenda-flow {
  display: flex;
  align-items: stretch;
  gap: 0;
  flex-wrap: wrap;
  justify-content: center;
}

.agenda-step {
  flex: 1;
  min-width: 160px;
  padding: 1.25rem;
  text-align: center;
  position: relative;
}

.agenda-step:not(:last-child)::after {
  content: '→';
  position: absolute;
  right: -0.6rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.2rem;
  color: var(--color-accent);
  font-weight: 700;
}

.agenda-step-label {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem 2rem;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
  border-radius: 50%;
  margin-bottom: 0.75rem;
}

.agenda-step-content {
  font-size: 0.85rem;
  color: var(--color-text);
  line-height: 1.6;
}

.agenda-step-content span {
  display: inline;
  color: var(--color-text-secondary);
  font-size: 0.8rem;
}

.agenda-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-accent);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0 0.25rem;
  min-width: 30px;
}

@media (max-width: 768px) {
  .agenda-flow {
    flex-direction: column;
    align-items: center;
  }

  .agenda-step:not(:last-child)::after {
    content: '↓';
    right: auto;
    bottom: -0.6rem;
    top: auto;
    left: 50%;
    transform: translateX(-50%);
  }

  .agenda-divider {
    padding: 0.25rem 0;
  }
}

/* --- Fade-in Animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Hero --- */
.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 3rem) 1.5rem 5rem;
  background: var(--color-bg);
}

.hero-content {
  max-width: 900px;
}

.hero-logo {
  width: auto;
  height: 100px;
  margin: 0 auto 2rem;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 2rem;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--color-accent);
  color: #fff;
  border-radius: 8px;
  font-weight: 500;
  font-size: 0.9rem;
  transition: background var(--transition);
}

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

/* --- About / Pillars --- */
.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.pillar-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.75rem;
  transition: transform var(--transition), box-shadow var(--transition);
}

.pillar-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--color-card-shadow);
}

.pillar-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
  border-radius: 50%;
  margin-bottom: 0.75rem;
}

.pillar-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.pillar-card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

.approach-block {
  margin-top: 2.5rem;
  padding: 1.5rem;
  background: var(--color-bg-alt);
  border-radius: 10px;
  border-left: 3px solid var(--color-accent);
}

.approach-block h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.approach-block p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* --- Workshop Card --- */
.workshop-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.75rem;
  transition: transform var(--transition), box-shadow var(--transition);
}

.workshop-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--color-card-shadow);
}

.workshop-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.workshop-card .workshop-overview {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.workshop-card .workshop-steps {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  padding-left: 1.25rem;
}

.workshop-card .workshop-steps li {
  margin-bottom: 0.4rem;
}

.workshop-card .workshop-steps ul {
  padding-left: 1.25rem;
  margin: 0.3rem 0;
  list-style: disc;
}

/* --- Projects --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}

.project-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--color-card-shadow);
}

.project-thumb {
  height: 180px;
  background: var(--color-bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  font-size: 0.85rem;
}

.project-body {
  padding: 1.5rem;
}

.project-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.75rem;
}

.project-body h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.project-body p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.project-link {
  font-size: 0.85rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

/* --- Members --- */
.members-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
}

.member-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.75rem;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}

.member-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--color-card-shadow);
}

.member-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--color-bg-alt);
  margin: 0 auto 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--color-text-secondary);
  overflow: hidden;
}

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

.member-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.member-role {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

.member-interests {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* --- Publications --- */
.pub-year-group {
  margin-bottom: 2rem;
}

.pub-year {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.pub-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.pub-item {
  padding: 1rem 1.25rem;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 0.9rem;
  line-height: 1.6;
}

.pub-item .pub-title {
  font-weight: 600;
}

.pub-item .pub-authors {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
}

.pub-item .pub-venue {
  color: var(--color-accent);
  font-size: 0.85rem;
  font-weight: 500;
}

.pub-item .pub-doi {
  font-size: 0.8rem;
}

/* --- News --- */
.news-timeline {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.news-item {
  display: flex;
  gap: 1.25rem;
  padding: 1rem 1.25rem;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  align-items: flex-start;
}

.news-date {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
  white-space: nowrap;
  min-width: 90px;
  padding-top: 0.1rem;
}

.news-content h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.news-content p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.news-tag {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.15rem 0.5rem;
  border-radius: 3px;
  margin-left: 0.5rem;
  vertical-align: middle;
}

.news-tag.event { background: #e8f4e8; color: #2d6a2d; }
.news-tag.paper { background: #e8e8f4; color: #2d2d6a; }
.news-tag.award { background: #f4e8e8; color: #6a2d2d; }
.news-tag.news { background: #f0f0f0; color: #555; }

[data-theme="dark"] .news-tag.event { background: #1a3a1a; color: #7ac57a; }
[data-theme="dark"] .news-tag.paper { background: #1a1a3a; color: #7a7ac5; }
[data-theme="dark"] .news-tag.award { background: #3a1a1a; color: #c57a7a; }
[data-theme="dark"] .news-tag.news { background: #2a2a2a; color: #aaa; }

/* --- Footer --- */
.site-footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding: 3rem 1.5rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2rem;
}

.footer-about p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin-top: 0.75rem;
}

.footer-heading {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  color: var(--color-text);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

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

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

.footer-bottom {
  max-width: var(--max-width);
  margin: 2rem auto 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
}

@media (max-width: 768px) {
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .news-item {
    flex-direction: column;
    gap: 0.5rem;
  }

  .news-date {
    min-width: auto;
  }
}

/* --- Utility --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}