/* ===== RESET & VARIABLES ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --color-primary: #1a2a3a;
  --color-primary-light: #2c5f8a;
  --color-primary-lighter: #4a90d9;
  --color-accent: #6c8db0;
  --color-gray-100: #f5f7fa;
  --color-gray-200: #e9edf2;
  --color-gray-300: #d0d7e0;
  --color-gray-500: #6b7a8a;
  --color-gray-700: #3d4a5a;
  --color-white: #ffffff;
  --color-text: #1e2a36;
  --shadow-sm: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 40px rgba(0,0,0,0.10);
  --radius: 12px;
  --transition: all 0.25s ease;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--color-gray-100);
  color: var(--color-text);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== HEADER ===== */
.site-header {
  background: var(--color-primary);
  color: var(--color-white);
  padding: 20px 0;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 16px;
}

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

.logo-text {
  font-weight: 600;
  font-size: 1.3rem;
  letter-spacing: -0.3px;
}
.logo-text small {
  font-weight: 400;
  font-size: 0.8rem;
  opacity: 0.8;
  display: block;
}

.header-nav {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}
.header-nav a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: var(--transition);
  border-bottom: 2px solid transparent;
  padding-bottom: 4px;
}
.header-nav a:hover {
  color: #fff;
  border-bottom-color: var(--color-primary-lighter);
}

/* ===== LANGUAGE SWITCHER ===== */
.lang-switcher {
  display: flex;
  gap: 4px;
  background: rgba(255,255,255,0.12);
  padding: 4px;
  border-radius: 30px;
}
.lang-btn {
  background: transparent;
  border: none;
  color: rgba(255,255,255,0.7);
  font-weight: 600;
  font-size: 0.8rem;
  padding: 6px 14px;
  border-radius: 30px;
  cursor: pointer;
  transition: var(--transition);
  font-family: 'Inter', sans-serif;
  letter-spacing: 0.3px;
}
.lang-btn:hover {
  color: #fff;
  background: rgba(255,255,255,0.1);
}
.lang-btn.active {
  background: var(--color-white);
  color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}
.lang-btn.active:hover {
  background: var(--color-white);
}

/* ===== HERO ===== */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: white;
  padding: 60px 0 50px;
  margin-bottom: 40px;
  border-radius: 0 0 40px 40px;
  text-align: center;
}
.hero h1 {
  font-size: 2.8rem;
  font-weight: 700;
  letter-spacing: -1px;
  margin-bottom: 12px;
}
.hero p {
  font-size: 1.2rem;
  opacity: 0.9;
  max-width: 720px;
  margin: 0 auto;
}

/* ===== SECTIONS ===== */
section {
  margin-bottom: 60px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--color-primary);
  margin-bottom: 32px;
  position: relative;
  display: inline-block;
}
.section-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -8px;
  width: 60px;
  height: 4px;
  background: var(--color-primary-lighter);
  border-radius: 4px;
}
.section-title.centered {
  display: block;
  text-align: center;
}
.section-title.centered::after {
  left: 50%;
  transform: translateX(-50%);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 32px;
  margin-top: 16px;
}

/* ===== MEMBER CARD ===== */
.member-card {
  background: var(--color-white);
  border-radius: var(--radius);
  padding: 28px 20px 24px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  text-align: center;
  border: 1px solid var(--color-gray-200);
}
.member-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-lighter);
}
.member-card img {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 16px;
  border: 4px solid var(--color-gray-200);
  transition: var(--transition);
}
.member-card:hover img {
  border-color: var(--color-primary-lighter);
}
.member-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-primary);
}
.member-card .role {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-primary-light);
  margin: 4px 0 12px;
}
.member-card .bio {
  font-size: 0.95rem;
  color: var(--color-gray-500);
  margin-bottom: 16px;
}
.member-card .contact {
  font-size: 0.9rem;
  color: var(--color-gray-700);
}
.member-card .contact i {
  width: 20px;
  color: var(--color-primary-light);
}
.member-card .link-more {
  display: inline-block;
  margin-top: 12px;
  font-weight: 500;
  color: var(--color-primary-lighter);
  text-decoration: none;
  font-size: 0.9rem;
  transition: var(--transition);
}
.member-card .link-more:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* ===== DIRECTOR ===== */
.director-card {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 40px;
  background: var(--color-white);
  border-radius: var(--radius);
  padding: 32px 36px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-gray-200);
  margin-top: 12px;
}
.director-card img {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--color-gray-200);
}
.director-info h2 {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-primary);
}
.director-info .role {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-primary-light);
  margin-bottom: 8px;
}
.director-info .contact {
  font-size: 0.95rem;
  color: var(--color-gray-700);
}
.director-info .contact i {
  width: 24px;
  color: var(--color-primary-light);
}

/* ===== PROJECT ===== */
.project-card {
  background: var(--color-white);
  border-radius: var(--radius);
  padding: 32px 36px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-gray-200);
  transition: var(--transition);
}
.project-card:hover {
  box-shadow: var(--shadow-md);
}
.project-card h3 {
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 12px;
}
.project-card .sub {
  font-weight: 500;
  color: var(--color-primary-light);
  margin-bottom: 16px;
}
.project-card ul {
  list-style: none;
  padding: 0;
}
.project-card ul li {
  padding-left: 24px;
  position: relative;
  margin-bottom: 8px;
}
.project-card ul li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--color-primary-lighter);
  font-weight: 700;
}
.project-card .badge {
  display: inline-block;
  background: var(--color-primary-light);
  color: white;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  margin-top: 12px;
  letter-spacing: 0.3px;
}
.project-card .dataset-link {
  display: inline-block;
  margin-top: 12px;
  margin-left: 12px;
  background: var(--color-gray-200);
  padding: 8px 20px;
  border-radius: 30px;
  color: var(--color-primary);
  font-weight: 500;
  text-decoration: none;
  transition: var(--transition);
}
.project-card .dataset-link:hover {
  background: var(--color-primary-lighter);
  color: white;
}

/* ===== PUBLICATIONS ===== */
.pub-section {
  background: var(--color-white);
  border-radius: var(--radius);
  padding: 28px 32px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-gray-200);
  margin-bottom: 24px;
}
.pub-section h4 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.pub-section h4 i {
  color: var(--color-primary-lighter);
}
.pub-list {
  list-style: none;
  padding: 0;
}
.pub-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--color-gray-200);
  font-size: 0.95rem;
}
.pub-list li:last-child {
  border-bottom: none;
}
.pub-list li a {
  color: var(--color-primary-light);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
}
.pub-list li a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}
.pub-list .doi {
  font-size: 0.85rem;
  color: var(--color-gray-500);
  margin-left: 6px;
}
.pub-list .badge-thesis {
  display: inline-block;
  background: var(--color-gray-200);
  font-size: 0.7rem;
  padding: 2px 10px;
  border-radius: 12px;
  margin-left: 8px;
  color: var(--color-gray-700);
}

/* ===== CONTACT / FOOTER ===== */
.contact-section {
  background: var(--color-primary);
  color: white;
  border-radius: var(--radius) var(--radius) 0 0;
  padding: 48px 36px;
  margin-top: 40px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
}
.contact-section .info {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.contact-section .info i {
  width: 28px;
  color: var(--color-primary-lighter);
}
.contact-section .socials {
  display: flex;
  gap: 20px;
}
.contact-section .socials a {
  color: rgba(255,255,255,0.8);
  font-size: 1.6rem;
  transition: var(--transition);
}
.contact-section .socials a:hover {
  color: #fff;
  transform: scale(1.1);
}

.footer-bottom {
  background: var(--color-primary);
  padding: 20px 0;
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
  color: rgba(255,255,255,0.6);
  font-size: 0.9rem;
}
.footer-bottom img {
  height: 40px;
  margin-top: 8px;
  filter: brightness(0) invert(1) opacity(0.7);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }
  .lang-switcher {
    align-self: flex-start;
  }
  .hero h1 {
    font-size: 2rem;
  }
  .director-card {
    flex-direction: column;
    text-align: center;
    padding: 24px;
  }
  .director-card img {
    width: 140px;
    height: 140px;
  }
  .section-title {
    font-size: 1.6rem;
  }
  .contact-section {
    flex-direction: column;
    text-align: center;
  }
  .project-card {
    padding: 24px;
  }
  .pub-section {
    padding: 20px;
  }
}
@media (max-width: 480px) {
  .hero {
    padding: 40px 0 30px;
  }
  .hero h1 {
    font-size: 1.6rem;
  }
  .member-card img {
    width: 100px;
    height: 100px;
  }
}