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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 0.75rem;
}

h1 {
    font-size: 3rem;
    font-weight: 700;
}

h2 {
    font-size: 2.25rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

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

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

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* 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(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-logo a {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 100px 0 60px;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.research-hero {
    min-height: 30vh;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.9) 0%, rgba(79, 70, 229, 0.9) 100%), url('images/header-bg.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    color: white;
}

.research-hero .hero-title,
.research-hero .hero-subtitle,
.research-hero .hero-description {
    color: white;
}

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

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.highlight {
    color: var(--primary-color);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

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

.profile-image {
    width: 100%;
    max-width: 400px;
    height: auto;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
}

/* Section Styles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* About Section */
.about {
    padding: 60px 0;
    background-color: var(--bg-primary);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.125rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* Research Section */
.research {
    padding: 60px 0;
    background-color: var(--bg-secondary);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.interest-card {
    background-color: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.interest-icon {
    width: 60px;
    height: 60px;
    background-color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
}

.research-icon i {
    font-size: 1.5rem;
    color: white;
}

.interest-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.interest-card p {
    color: var(--text-secondary);
    line-height: 1.5;
}

.research-actions {
    text-align: center;
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Research Interests Section */
.research-interests {
    padding: 60px 0;
    background-color: var(--bg-primary);
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
}

.interest-card {
    background-color: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.interest-icon {
    width: 60px;
    height: 60px;
    background-color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
}

.interest-icon i {
    font-size: 1.5rem;
    color: white;
}

.interest-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.interest-card p {
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 0.75rem;
}

/* Venue Summary Section */
.venue-summary {
    padding: 60px 0;
    background-color: var(--bg-primary);
}

.venue-stats {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.venue-category {
    background-color: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.venue-category h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.venue-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.venue-tag {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 500;
    font-size: 0.875rem;
    text-align: center;
    transition: var(--transition);
    border: 1px solid;
}

.venue-tag.high {
    background-color: #dc2626;
    color: white;
    border-color: #b91c1c;
}

.venue-tag.medium {
    background-color: #f59e0b;
    color: white;
    border-color: #d97706;
}

.venue-tag.low {
    background-color: #059669;
    color: white;
    border-color: #047857;
}

.venue-tag.single {
    background-color: var(--bg-primary);
    color: var(--text-secondary);
    border-color: var(--border-color);
}

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

/* Publications Section */
.publications {
    padding: 60px 0;
    background-color: var(--bg-secondary);
}

.publications-container {
    max-width: 1000px;
    margin: 0 auto;
}

.year-section {
    margin-bottom: 2rem;
}

.year-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--primary-color);
}

.publication-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.publication-item {
    background-color: var(--bg-primary);
    padding: 1.25rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

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

.publication-item h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.publication-item .authors {
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.publication-item .venue {
    font-style: italic;
    color: var(--text-light);
    margin-bottom: 0.75rem;
}

.publication-links {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.load-more-container {
    text-align: center;
    margin-top: 1.5rem;
}

/* Academic Services Section */
.academic-services {
    padding: 60px 0;
    background-color: var(--bg-primary);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.service-card {
    background-color: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.service-card h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.service-card ul {
    list-style: none;
}

.service-card li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.service-card li:last-child {
    border-bottom: none;
}

/* Presentations Section */
.presentations {
    padding: 60px 0;
    background-color: var(--bg-secondary);
}

.presentations-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.presentation-item {
    background-color: var(--bg-primary);
    padding: 1.25rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.presentation-date {
    background-color: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 0.875rem;
    white-space: nowrap;
    flex-shrink: 0;
}

.presentation-content {
    flex: 1;
}

.presentation-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.presentation-content p {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

/* Podcast Section */
.podcast {
    padding: 60px 0;
    background-color: var(--bg-primary);
}

.podcast-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
}

.podcast-text {
    padding-right: 2rem;
}

.podcast-player {
    width: 100%;
}

/* Partnerships Section */
.partnerships {
    padding: 60px 0;
    background-color: var(--bg-secondary);
}

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

.partnerships-content p {
    font-size: 1.125rem;
    line-height: 1.6;
}

/* Footer */
.footer {
    background-color: var(--bg-dark);
    color: white;
    padding: 40px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.footer-section h3,
.footer-section h4 {
    color: white;
    margin-bottom: 0.75rem;
}

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

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

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

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

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background-color: var(--secondary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
}

.footer-bottom {
    border-top: 1px solid var(--secondary-color);
    padding-top: 1.5rem;
    text-align: center;
    color: var(--text-light);
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 60px;
        flex-direction: column;
        background-color: var(--bg-primary);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 1.5rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        margin: 0.75rem 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 1.5rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-buttons {
        justify-content: center;
    }

    .section-title {
        font-size: 2rem;
    }

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

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

    .venue-category {
        padding: 1.25rem;
    }

    .venue-tags {
        gap: 0.5rem;
    }

    .venue-tag {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }
}    .podcast-content {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .podcast-text {
        padding-right: 0;
    }

    .research-actions {
        flex-direction: column;
        align-items: center;
    }

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

    .presentation-item {
        flex-direction: column;
        gap: 0.75rem;
    }

    .presentation-date {
        align-self: flex-start;
    }

    .container {
        padding: 0 1rem;
    }

    .nav-container {
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.125rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .btn {
        padding: 0.625rem 1.25rem;
        font-size: 0.875rem;
    }

    .year-title {
        font-size: 1.5rem;
    }

    .publication-item {
        padding: 1rem;
    }

    .interest-card,
    .service-card {
        padding: 1.25rem;
    }

    .venue-category {
        padding: 1rem;
    }

    .venue-tag {
        padding: 0.375rem 0.75rem;
        font-size: 0.75rem;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Smooth scrolling for anchor links */
html {
    scroll-padding-top: 80px;
}