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

:root {
    --color-black: #1a1a1a;
    --color-dark-gray: #2d2d2d;
    --color-gray: #6b6b6b;
    --color-light-gray: #e5e5e5;
    --color-off-white: #f8f8f8;
    --color-white: #ffffff;
    --color-accent: #000000;
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 3.5rem;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--color-black);
    background-color: var(--color-white);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

a {
    color: inherit;
    text-decoration: none;
    transition: opacity 0.2s ease;
}

a:hover {
    opacity: 0.7;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-light-gray);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

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

.nav-brand h1 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--color-black);
    margin-bottom: 0.25rem;
}

.nav-subtitle {
    font-size: 0.85rem;
    color: var(--color-gray);
    font-weight: 400;
}

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

.nav-menu a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-black);
    transition: color 0.2s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--color-gray);
}

.cta-link {
    padding: 0.5rem 1.25rem;
    background-color: var(--color-black);
    color: var(--color-white) !important;
    border-radius: 4px;
}

.cta-link:hover {
    opacity: 0.8;
    color: var(--color-white) !important;
}

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: var(--spacing-sm) 0 0 0;
    background-color: var(--color-white);
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-xs);
    color: var(--color-black);
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--color-gray);
    margin-bottom: 0;
    line-height: 1.6;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 4px;
    transition: all 0.2s ease;
    cursor: pointer;
    border: 1px solid transparent;
}

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

.btn-primary:hover {
    opacity: 0.85;
}

.btn-secondary {
    background-color: var(--color-white);
    color: var(--color-black);
    border: 1px solid var(--color-black);
}

.btn-secondary:hover {
    background-color: var(--color-off-white);
}

/* Leadership Section */
.leadership {
    padding: var(--spacing-md) 0;
    background-color: var(--color-off-white);
    border-bottom: 1px solid var(--color-light-gray);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: #2c5aa0;
}

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

.co-pis {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: var(--spacing-md);
}

.co-pi-card {
    background-color: var(--color-white);
    padding: var(--spacing-md);
    border-radius: 8px;
    border: 1px solid var(--color-light-gray);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.co-pi-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.co-pi-header {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
}

.co-pi-photo {
    width: 120px;
    height: 120px;
    object-fit: cover;
    border-radius: 4px;
    flex-shrink: 0;
    border: 2px solid var(--color-light-gray);
}

.co-pi-info {
    flex: 1;
}

.co-pi-info h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.co-pi-info .title {
    font-size: 0.95rem;
    color: var(--color-gray);
    margin-bottom: 0.15rem;
}

.co-pi-info .affiliation {
    font-size: 0.9rem;
    color: var(--color-gray);
}

.co-pi-bio {
    padding-left: 0;
}

.co-pi-bio p {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--color-dark-gray);
    margin-bottom: var(--spacing-sm);
}

.link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-black);
    text-decoration: underline;
}

/* About Section */
.about {
    padding: var(--spacing-md) 0 var(--spacing-xl) 0;
    background-color: var(--color-white);
}

/* About section uses vertical stacking - no grid needed */

.about-content {
    margin-bottom: var(--spacing-lg);
}

.about-content h2 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: #2c5aa0;
}

.research-areas-overview {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.area-column {
    text-align: center;
    padding: var(--spacing-sm);
}

.area-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
}

.area-column h4 {
    font-size: 1.15rem;
    font-weight: 600;
    line-height: 1.3;
    color: #2c5aa0;
    margin-bottom: var(--spacing-xs);
}

.area-description {
    font-size: 0.85rem;
    color: var(--color-gray);
    line-height: 1.5;
}

@media (max-width: 768px) {
    .research-areas-overview {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }
}

.about-content .lead {
    font-size: 1.05rem;
    font-weight: 400;
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
    color: var(--color-dark-gray);
}

.about-content p {
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--color-dark-gray);
    margin-bottom: var(--spacing-sm);
}

.about-focus h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.focus-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.focus-item {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background-color: var(--color-off-white);
    border-radius: 6px;
    border: 1px solid var(--color-light-gray);
}

.focus-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.focus-item h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.focus-item p {
    font-size: 0.9rem;
    color: var(--color-gray);
    line-height: 1.5;
}

/* Research Section */
.research {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-off-white);
}

.research-category {
    margin-bottom: var(--spacing-xl);
}

.category-title {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-black);
}

.category-blurb {
    font-size: 1rem;
    color: var(--color-dark-gray);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
    font-style: italic;
}

.category-description {
    font-size: 1rem;
    color: var(--color-gray);
    font-style: italic;
}

.papers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.paper-card {
    background-color: var(--color-white);
    padding: var(--spacing-md);
    border-radius: 6px;
    border: 1px solid var(--color-light-gray);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.paper-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.paper-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.paper-card .authors {
    font-size: 0.9rem;
    color: var(--color-gray);
    margin-bottom: 0.25rem;
}

.paper-card .year {
    font-size: 0.85rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-sm);
}

.paper-link {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-black);
    text-decoration: underline;
}

/* Media Coverage Section */
.media {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-white);
    border-top: 1px solid var(--color-light-gray);
}

.media-grid {
    display: grid;
    gap: var(--spacing-xl);
}

.media-category {
    margin-bottom: var(--spacing-lg);
}

.media-outlet {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-black);
}

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

.media-article {
    background-color: var(--color-off-white);
    padding: var(--spacing-md);
    border-radius: 6px;
    border: 1px solid var(--color-light-gray);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.media-article:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.media-article h4 {
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    line-height: 1.4;
    color: var(--color-black);
}

.media-date {
    font-size: 0.85rem;
    color: var(--color-gray);
}

.media-article a {
    display: block;
}

/* Team Section */
.team {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-off-white);
}

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

.team-section-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-black);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.team-member {
    background-color: var(--color-off-white);
    padding: var(--spacing-md);
    border-radius: 6px;
    border: 1px solid var(--color-light-gray);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.team-member:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.member-info h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.member-title {
    font-size: 0.9rem;
    color: var(--color-gray);
    margin-bottom: 0.25rem;
}

.member-affiliation {
    font-size: 0.85rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-sm);
}

.member-info a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-black);
    text-decoration: underline;
}

/* Collaborate Section */
.collaborate {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-black);
    color: var(--color-white);
}

.collaborate-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.collaborate-content h2 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.collaborate-content .lead {
    font-size: 1.25rem;
    color: var(--color-light-gray);
    margin-bottom: var(--spacing-lg);
}

.collaborate-benefits {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    text-align: left;
}

.benefit {
    padding: var(--spacing-md);
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.benefit h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.benefit p {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--color-light-gray);
}

.contact-cta {
    margin-top: var(--spacing-lg);
}

.contact-cta p {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-light-gray);
}

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

.collaborate .btn-primary:hover {
    background-color: var(--color-light-gray);
}

/* Footer */
.footer {
    background-color: var(--color-dark-gray);
    color: var(--color-white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.footer-section h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.footer-section p {
    font-size: 0.9rem;
    color: var(--color-light-gray);
    margin-bottom: 0.25rem;
}

.footer-section a {
    color: var(--color-light-gray);
}

.footer-section a:hover {
    color: var(--color-white);
}

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

.footer-section li {
    margin-bottom: 0.25rem;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 0.85rem;
    color: var(--color-light-gray);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .nav-menu {
        display: none;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .co-pis {
        grid-template-columns: 1fr;
    }

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

    .section-header h2 {
        font-size: 2rem;
    }

    .collaborate-content h2 {
        font-size: 2rem;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Selection */
::selection {
    background-color: var(--color-black);
    color: var(--color-white);
}

/* Collapsible Research Topics */
.research-topics {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.research-topic {
    background-color: var(--color-white);
    border: 1px solid var(--color-light-gray);
    border-radius: 6px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.topic-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.topic-header:hover {
    background-color: var(--color-off-white);
}

.topic-info {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    flex: 1;
}

.topic-icon {
    font-size: 1.75rem;
    flex-shrink: 0;
    margin-top: 0.25rem;
}

.topic-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-black);
}

.topic-blurb {
    font-size: 0.95rem;
    color: var(--color-gray);
    line-height: 1.5;
    font-style: italic;
}

.topic-toggle {
    font-size: 2rem;
    font-weight: 300;
    color: var(--color-black);
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
}

.research-topic.active .topic-toggle {
    transform: rotate(45deg);
}

.topic-papers {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.topic-papers .papers-grid {
    padding: 0 var(--spacing-md) var(--spacing-md);
}