/* ============================================
   CSS Variables
   ============================================ */
:root {
    /* Colors - Sophisticated navy and warm earth tones */
    --primary: #1a3a52;
    --primary-light: #2d5166;
    --primary-dark: #0f2838;
    --accent: #d4a574;
    --accent-light: #e8c9a0;
    --text-dark: #2c2c2c;
    --text-medium: #5a5a5a;
    --text-light: #8a8a8a;
    --bg-light: #fafaf8;
    --bg-white: #ffffff;
    --border: #e5e5e0;
    
    /* Typography */
    --font-display: 'Cormorant Garamond', Georgia, serif;
    --font-body: 'Work Sans', -apple-system, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Other */
    --radius: 2px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-dark);
    background: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.3;
    color: var(--primary-dark);
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 400;
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 400;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

p {
    margin-bottom: var(--spacing-sm);
}

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

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

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

/* ============================================
   Container & Layout
   ============================================ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    flex-direction: column;
    text-decoration: none;
}

.logo-main {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--primary-dark);
    line-height: 1.2;
}

.logo-sub {
    font-family: var(--font-body);
    font-size: 0.75rem;
    color: var(--text-light);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
    list-style: none;
}

.nav-menu a {
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--text-medium);
    padding: var(--spacing-xs) 0;
    position: relative;
}

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

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

.nav-menu a.active {
    color: var(--primary-dark);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    padding: var(--spacing-xl) var(--spacing-md);
    max-width: 1200px;
    margin: 0 auto;
}

.hero-content h1 {
    margin-bottom: var(--spacing-md);
    color: var(--primary-dark);
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-medium);
    line-height: 1.6;
}

.hero-image {
    position: relative;
}

.hero-image img {
    width: 100%;
    height: auto;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
}

/* ============================================
   Mission Section
   ============================================ */
.mission {
    background: var(--bg-light);
    padding: var(--spacing-xl) var(--spacing-md);
}

.mission-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.mission h2 {
    margin-bottom: var(--spacing-md);
}

.mission p {
    font-size: 1.1rem;
    color: var(--text-medium);
    margin-bottom: var(--spacing-md);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-block;
    padding: 0.9rem 2rem;
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: var(--radius);
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-family: var(--font-body);
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--accent);
    color: var(--primary-dark);
}

.btn-secondary:hover {
    background: var(--accent-light);
    transform: translateY(-1px);
}

/* ============================================
   Highlights Section
   ============================================ */
.highlights {
    padding: var(--spacing-xl) var(--spacing-md);
}

.highlights-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.highlight-card {
    padding: var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: var(--transition);
    background: var(--bg-white);
}

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

.card-icon {
    width: 48px;
    height: 48px;
    color: var(--accent);
    margin-bottom: var(--spacing-sm);
}

.highlight-card h3 {
    font-size: 1.4rem;
    margin-bottom: var(--spacing-sm);
}

.highlight-card p {
    color: var(--text-medium);
    margin-bottom: var(--spacing-sm);
}

.highlight-card a {
    font-weight: 500;
    color: var(--primary);
}

/* ============================================
   News/Jobs Section
   ============================================ */
.news-jobs {
    background: var(--primary-dark);
    color: white;
    padding: var(--spacing-xl) var(--spacing-md);
}

.content-box {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.news-jobs h2 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.news-jobs p {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-md);
    color: rgba(255, 255, 255, 0.9);
}

/* ============================================
   Affiliations
   ============================================ */
.affiliations {
    padding: var(--spacing-md);
    text-align: center;
}

.affiliations h3 {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-light);
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-body);
}

.affiliation-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.affiliation-links a {
    font-size: 0.9rem;
    color: var(--text-medium);
}

/* ============================================
   Page Header
   ============================================ */
.page-header {
    background: var(--bg-light);
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    border-bottom: 1px solid var(--border);
}

.page-header h1 {
    margin-bottom: var(--spacing-xs);
}

.page-subtitle {
    font-size: 1.1rem;
    color: var(--text-medium);
}

/* ============================================
   Team Section
   ============================================ */
.team-section {
    padding: var(--spacing-xl) var(--spacing-md);
}

.team-member {
    margin-bottom: var(--spacing-lg);
}

.team-member.featured {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: var(--spacing-md);
    padding-bottom: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--border);
}

.team-grid {
    display: grid;
    gap: var(--spacing-lg);
}

.team-grid .team-member {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: var(--transition);
}

.team-grid .team-member:hover {
    box-shadow: var(--shadow-sm);
}

.member-photo img {
    width: 100%;
    border-radius: var(--radius);
}

.member-info h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
}

.member-info h3 {
    font-size: 1.4rem;
    margin-bottom: var(--spacing-xs);
}

.member-title {
    color: var(--text-medium);
    margin-bottom: var(--spacing-sm);
}

.member-education {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
    margin-bottom: var(--spacing-xs);
}

.member-research {
    margin-bottom: var(--spacing-sm);
    color: var(--text-medium);
}

.member-contact,
.member-email {
    font-size: 0.95rem;
    color: var(--text-light);
}

/* ============================================
   Research Section
   ============================================ */
.research-areas {
    padding: var(--spacing-xl) var(--spacing-md);
}

.research-item {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--border);
}

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

.research-visual img {
    width: 100%;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
}

.research-content h2 {
    margin-bottom: var(--spacing-md);
}

.research-content p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-medium);
}

/* ============================================
   Publications Section
   ============================================ */
.publications {
    padding: var(--spacing-xl) var(--spacing-md);
}

.publication-list {
    list-style: none;
    counter-reset: pub-counter;
}

.publication-item {
    counter-increment: pub-counter;
    position: relative;
    padding-left: 3rem;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border);
}

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

.publication-item::before {
    content: counter(pub-counter);
    position: absolute;
    left: 0;
    top: 0;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent);
}

.publication-item .authors {
    font-weight: 600;
    color: var(--primary-dark);
}

.publication-item .title {
    color: var(--primary);
    font-weight: 500;
    display: inline;
}

.publication-item .title:hover {
    text-decoration: underline;
}

.publication-item .journal {
    font-style: italic;
    color: var(--text-medium);
}

.publication-item .year,
.publication-item .volume,
.publication-item .doi,
.publication-item .pmid,
.publication-item .pmcid,
.publication-item .date {
    color: var(--text-light);
    font-size: 0.95rem;
}

.pdf-link {
    display: inline-block;
    margin-top: var(--spacing-xs);
    font-size: 0.9rem;
    color: var(--accent);
    font-weight: 500;
}

/* ============================================
   Datasets Section
   ============================================ */
.datasets {
    padding: var(--spacing-xl) var(--spacing-md);
}

.dataset-item {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--border);
}

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

.dataset-item h2 {
    margin-bottom: var(--spacing-sm);
}

.dataset-citation {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: var(--spacing-xs);
}

.dataset-description {
    color: var(--text-medium);
    margin-bottom: var(--spacing-md);
}

.dataset-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.link-item {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--bg-light);
    border-radius: var(--radius);
}

.link-label {
    font-weight: 600;
    color: var(--primary);
    min-width: 2rem;
}

.link-text {
    flex: 1;
}

/* ============================================
   Contact Section
   ============================================ */
.contact {
    padding: var(--spacing-xl) var(--spacing-md);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}

.contact-info h2 {
    margin-bottom: var(--spacing-md);
}

.contact-address {
    color: var(--text-medium);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.contact-section {
    margin-bottom: var(--spacing-lg);
}

.contact-section h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary);
}

.contact-section p {
    color: var(--text-medium);
}

.contact-links-section h2 {
    margin-bottom: var(--spacing-md);
}

.resource-card {
    padding: var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: var(--spacing-md);
    background: var(--bg-light);
}

.resource-card h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
}

.resource-card p {
    color: var(--text-medium);
    margin-bottom: var(--spacing-sm);
}

/* ============================================
   Footer
   ============================================ */
footer {
    background: var(--primary-dark);
    color: rgba(255, 255, 255, 0.7);
    padding: var(--spacing-md);
    text-align: center;
    font-size: 0.9rem;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg-white);
        border-bottom: 1px solid var(--border);
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
        display: none;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .hero {
        grid-template-columns: 1fr;
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .hero-image {
        order: -1;
    }
    
    .team-member.featured,
    .team-grid .team-member {
        grid-template-columns: 1fr;
    }
    
    .research-item {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero, .mission, .highlights, .team-section, .research-areas, .publications, .datasets, .contact {
    animation: fadeIn 0.6s ease-out;
}