/* ============================================
   Reconfigurable AI-Chip共創研究所 - Stylesheet
   ============================================ */

/* --- CSS Variables --- */
:root {
  --color-primary: #c8102e;
  --color-secondary: #1a1a3a;
  --color-tertiary: #5c3a6e;
  --color-bg: #ffffff;
  --color-bg-alt: #f7f8fa;
  --color-text: #2d2d2d;
  --color-text-muted: #666666;
  --color-border: #e0e0e0;
  --font-body: "Noto Sans JP", "Roboto", sans-serif;
  --max-width: 1100px;
  --header-height: 70px;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: opacity 0.2s;
}

a:hover {
  opacity: 0.7;
}

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

/* --- Utility --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.section-title::after {
  content: "";
  display: block;
  width: 40px;
  height: 3px;
  background: var(--color-primary);
  margin-top: 8px;
}

.section-padding {
  padding: 80px 0;
}

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

/* ============================================
   Header / Navigation
   ============================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.header-logo img {
  height: 44px;
  width: auto;
}

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav a {
  color: var(--color-text);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 4px;
  transition: background 0.2s, color 0.2s;
  white-space: nowrap;
}

.nav a:hover,
.nav a.active {
  background: var(--color-bg-alt);
  color: var(--color-primary);
  opacity: 1;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-left: 16px;
  padding: 4px 12px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-secondary);
  transition: border-color 0.2s;
}

.lang-switch:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  opacity: 1;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-secondary);
  border-radius: 1px;
  transition: transform 0.3s, opacity 0.3s;
}

.hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.hamburger.open span:nth-child(2) {
  opacity: 0;
}

.hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  position: relative;
  padding: 100px 0 80px;
  background: var(--color-bg);
  background-image: url("../images/hero-bg.svg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  overflow: hidden;
}

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

.hero-logo {
  width: 280px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-secondary);
  line-height: 1.4;
  margin-bottom: 16px;
}

.hero-accent-line {
  width: 60px;
  height: 3px;
  background: var(--color-primary);
  margin-bottom: 20px;
}

.hero p {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  max-width: 640px;
  line-height: 1.9;
}

/* ============================================
   About Section
   ============================================ */
.about-layout {
  display: flex;
  gap: 48px;
  align-items: center;
}

.about-content {
  flex: 1;
  line-height: 2;
}

.about-content p + p {
  margin-top: 16px;
}

.about-illustration {
  width: 340px;
  flex-shrink: 0;
}

.about-illustration img {
  width: 100%;
  display: block;
}

/* ============================================
   News Section
   ============================================ */
.news-list {
  list-style: none;
}

.news-item {
  padding: 20px 0;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  gap: 20px;
  align-items: baseline;
}

.news-item:first-child {
  padding-top: 0;
}

.news-date {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  white-space: nowrap;
  min-width: 100px;
}

.news-tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 3px;
  background: var(--color-primary);
  color: #fff;
  margin-right: 8px;
  vertical-align: middle;
}

.news-title {
  font-weight: 500;
}

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

.btn-more {
  display: inline-block;
  margin-top: 24px;
  padding: 8px 24px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 0.875rem;
  color: var(--color-text);
  cursor: pointer;
  background: none;
  font-family: var(--font-body);
  transition: border-color 0.2s, color 0.2s;
}

.btn-more:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ============================================
   Members Section
   ============================================ */
.members-group + .members-group {
  margin-top: 48px;
}

.members-group-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-secondary);
  margin-bottom: 24px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-border);
}

.members-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 24px;
}

.member-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 24px;
  text-align: center;
  transition: box-shadow 0.2s;
}

.member-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.member-photo {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 16px;
  background: var(--color-bg-alt);
}

/* Placeholder when no photo */
.member-photo-placeholder {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: var(--color-bg-alt);
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 2rem;
}

.member-name {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-secondary);
  margin-bottom: 4px;
}

.member-role {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.member-field {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ============================================
   Research Section
   ============================================ */
.research-list {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.research-item {
  display: flex;
  gap: 32px;
  align-items: flex-start;
}

.research-item-text {
  flex: 1;
}

.research-item-text h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-secondary);
  margin-bottom: 12px;
  padding-left: 16px;
  border-left: 3px solid var(--color-primary);
}

.research-item-text p {
  line-height: 2;
}

.research-item-image {
  width: 280px;
  flex-shrink: 0;
  border-radius: 8px;
  overflow: hidden;
}

.research-item-image img {
  width: 100%;
  display: block;
}

/* ============================================
   Publications Section
   ============================================ */
.pub-year-group + .pub-year-group {
  margin-top: 36px;
}

.pub-year {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: 16px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}

.pub-list {
  list-style: none;
}

.pub-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--color-border);
  line-height: 1.8;
}

.pub-item:last-child {
  border-bottom: none;
}

.pub-authors {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.pub-title {
  font-weight: 600;
  color: var(--color-text);
}

.pub-venue {
  font-size: 0.9375rem;
  font-style: italic;
  color: var(--color-text-muted);
}

.pub-tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 3px;
  background: var(--color-secondary);
  color: #fff;
  margin-left: 6px;
  vertical-align: middle;
}

.pub-link {
  font-size: 0.875rem;
  margin-left: 8px;
}

/* ============================================
   Access Section
   ============================================ */
.access-content {
  display: flex;
  gap: 40px;
  align-items: flex-start;
}

.access-info {
  flex: 1;
}

.access-info h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-secondary);
  margin-bottom: 12px;
}

.access-info p {
  line-height: 2;
}

.access-info p + h3 {
  margin-top: 24px;
}

.access-map {
  flex: 1;
  min-height: 300px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.access-map iframe {
  width: 100%;
  height: 300px;
  border: none;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--color-secondary);
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
  font-size: 0.875rem;
  text-align: center;
}

.footer a {
  color: rgba(255, 255, 255, 0.85);
}

.footer a:hover {
  color: #fff;
  opacity: 1;
}

.footer-links {
  margin-bottom: 16px;
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-copy {
  color: rgba(255, 255, 255, 0.5);
}

/* ============================================
   Responsive
   ============================================ */

/* Tablet */
@media (max-width: 1023px) {
  .hero-logo {
    width: 220px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .about-layout {
    flex-direction: column;
  }

  .about-illustration {
    width: 100%;
    max-width: 340px;
  }

  .research-item {
    flex-direction: column;
  }

  .research-item-image {
    width: 100%;
    max-width: 400px;
  }

  .access-content {
    flex-direction: column;
  }

  .access-map {
    width: 100%;
  }
}

/* Mobile */
@media (max-width: 767px) {
  :root {
    --header-height: 60px;
  }

  .hamburger {
    display: flex;
  }

  .nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    flex-direction: column;
    padding: 16px 24px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 10px 0;
    font-size: 0.9375rem;
  }

  .lang-switch {
    margin-left: 0;
    margin-top: 8px;
    align-self: flex-start;
  }

  .hero {
    padding: 60px 0 50px;
  }

  .hero-logo {
    width: 200px;
  }

  .hero h1 {
    font-size: 1.5rem;
  }

  .section-padding {
    padding: 50px 0;
  }

  .section-title {
    font-size: 1.375rem;
  }

  .news-item {
    flex-direction: column;
    gap: 4px;
  }

  .members-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 16px;
  }

  .member-card {
    padding: 16px;
  }

  .member-photo,
  .member-photo-placeholder {
    width: 80px;
    height: 80px;
  }
}