/* ===== CSS Variables ===== */
:root {
  --primary: #0066cc;
  --primary-dark: #004d99;
  --primary-light: #3399ff;
  --secondary: #1a1a2e;
  --accent: #00d4ff;
  --text-dark: #1a1a2e;
  --text-light: #666;
  --text-muted: #888;
  --bg-light: #f8f9fa;
  --bg-dark: #0a0a14;
  --white: #ffffff;
  --border: #e0e0e0;
  --gradient-primary: linear-gradient(135deg, #0066cc 0%, #00d4ff 100%);
  --gradient-dark: linear-gradient(135deg, #1a1a2e 0%, #2d2d44 100%);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.16);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --transition: all 0.3s ease;
}

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

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text-dark);
  line-height: 1.6;
  background: var(--white);
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p { margin-bottom: 1rem; }

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

a:hover {
  color: var(--primary-dark);
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* ===== Navigation ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.navbar {
  padding: 1rem 0;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.logo-img {
  height: 5.0em;
  width: auto;
}

.logo-text-wrap {
  display: flex;
  flex-direction: column;
}

.logo-text {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.logo-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-menu a {
  color: var(--text-dark);
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
}

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

.nav-menu a:hover::after,
.nav-menu a.active::after {
  width: 100%;
}

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

.nav-toggle span {
  width: 25px;
  height: 2px;
  background: var(--text-dark);
  transition: var(--transition);
}

/* ===== Hero Section ===== */
.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  background: var(--gradient-dark);
  color: var(--white);
  padding-top: 120px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('../images/hero-bg.png') center/cover;
  opacity: 0.15;
}

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

.hero-content {
  max-width: 700px;
}

.hero-badge {
  display: inline-block;
  background: rgba(0, 212, 255, 0.2);
  color: var(--accent);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  border: 1px solid rgba(0, 212, 255, 0.3);
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  line-height: 1.1;
}

.hero h1 span {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.25rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 2rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--white);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.5);
  color: var(--white);
}

/* ===== Sections ===== */
section {
  padding: 6rem 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 4rem;
}

.section-header h2 {
  color: var(--text-dark);
  margin-bottom: 1rem;
}

.section-header p {
  color: var(--text-light);
  font-size: 1.125rem;
}

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

.section-dark {
  background: var(--secondary);
  color: var(--white);
}

.section-dark .section-header h2 {
  color: var(--white);
}

.section-dark .section-header p {
  color: rgba(255, 255, 255, 0.7);
}

/* ===== Research Areas ===== */
.research-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.research-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--border);
}

.research-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.research-icon {
  width: 64px;
  height: 64px;
  background: var(--gradient-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  font-size: 2rem;
}

.research-card h3 {
  margin-bottom: 1rem;
}

.research-card p {
  color: var(--text-light);
  margin-bottom: 1.5rem;
}

.research-card ul {
  list-style: none;
  margin-bottom: 1.5rem;
}

.research-card li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-light);
}

.research-card li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: bold;
}

/* ===== Stats ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.stat-item {
  text-align: center;
  padding: 1.5rem;
}

.stats-section-compact {
  padding: 3rem 0;
}

.stat-number {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 3.5rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.stat-number-small {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 3.5rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 1rem;
  color: var(--text-light);
}

/* ===== Team Grid ===== */
.team-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.team-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  text-align: center;
}

.team-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.team-photo {
  width: 100%;
  aspect-ratio: 1;
  background: var(--bg-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  color: var(--text-muted);
  overflow: hidden;
}

.team-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.team-info {
  padding: 1.5rem;
}

.team-info h4 {
  margin-bottom: 0.25rem;
}

.team-info .role {
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.team-info .affiliation {
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* ===== CTA Section ===== */
.cta-section {
  background: var(--gradient-primary);
  color: var(--white);
  text-align: center;
  padding: 5rem 0;
}

.cta-section h2 {
  color: var(--white);
  margin-bottom: 1rem;
}

.cta-section p {
  font-size: 1.25rem;
  opacity: 0.9;
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.cta-section .btn-outline {
  border-color: var(--white);
  color: var(--white);
}

.cta-section .btn-outline:hover {
  background: var(--white);
  color: var(--primary);
}

/* ===== Recruiting ===== */
.positions-list {
  max-width: 800px;
  margin: 0 auto;
}

.position-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
}

.position-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.position-info h3 {
  margin-bottom: 0.5rem;
}

.position-meta {
  display: flex;
  gap: 1.5rem;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.position-meta span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* ===== Page Header ===== */
.page-header {
  background: var(--gradient-dark);
  color: var(--white);
  padding: 8rem 0 4rem;
  text-align: center;
}

.page-header h1 {
  margin-bottom: 1rem;
}

.page-header .subtitle {
  font-size: 1.25rem;
  opacity: 0.8;
}

.page-content {
  padding: 4rem 0;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--secondary);
  color: rgba(255, 255, 255, 0.8);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-about h3 {
  color: var(--white);
  margin-bottom: 1rem;
}

.site-footer h4 {
  color: var(--white);
  margin-bottom: 1rem;
  font-size: 1rem;
}

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

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

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
}

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

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  text-align: center;
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.5);
}

/* ===== Benefits Grid ===== */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.benefit-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

.benefit-icon {
  width: 60px;
  height: 60px;
  background: var(--bg-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-size: 1.5rem;
}

.benefit-card h4 {
  margin-bottom: 0.5rem;
}

.benefit-card p {
  color: var(--text-light);
  font-size: 0.9375rem;
  margin-bottom: 0;
}

/* ===== Partner Grid ===== */
.partner-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 2rem;
}

.partner-item {
  text-align: center;
  padding: 1.5rem 1rem;
}

.partner-item img {
  height: 60px;
  width: auto;
  object-fit: contain;
  margin-bottom: 0.75rem;
}

.partner-item p {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 0;
}

/* ===== 5D Card Image ===== */
.card-image {
  width: auto;
  max-width: 100%;
  max-height: 300px;
  margin: 1rem auto;
  display: block;
  border-radius: var(--radius-md);
}

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

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .team-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .benefits-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .partner-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 1.25rem;
  }

  section {
    padding: 3.5rem 0;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 2rem;
    gap: 1rem;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    border-bottom: 1px solid var(--border);
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .hero {
    min-height: 50vh;
    padding-top: 90px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  h3 {
    font-size: 1.2rem;
  }

  .section-header {
    margin-bottom: 2.5rem;
  }

  .section-header p {
    font-size: 1rem;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .research-grid {
    grid-template-columns: 1fr !important;
  }

  .research-card {
    padding: 1.5rem;
  }

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

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

  .position-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

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

  .partner-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .btn {
    padding: 0.75rem 1.5rem;
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  section {
    padding: 2.5rem 0;
  }

  .hero {
    min-height: 45vh;
    padding-top: 80px;
  }

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

  h2 {
    font-size: 1.35rem;
  }

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

  .partner-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .hero-buttons .btn {
    width: 100%;
    text-align: center;
  }

  .logo-text {
    font-size: 1rem;
  }

  .logo-subtitle {
    font-size: 0.55rem;
  }
}