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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-alt: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

html {
    scroll-behavior: smooth;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background-color: var(--bg-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

/* Hero Section */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    align-items: center;
}

.hero-image img {
    width: 100%;
    max-width: 300px;
    border-radius: 50%;
    border: 5px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-lg);
}

.hero-text h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.subtitle {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    opacity: 0.95;
}

.affiliation {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.social-links a {
    color: white;
    font-size: 1.5rem;
    transition: transform 0.3s ease, opacity 0.3s ease;
    opacity: 0.9;
}

.social-links a:hover {
    transform: scale(1.2);
    opacity: 1;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
}

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

.btn-primary:hover {
    background-color: rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

/* Sections */
.section {
    padding: 4rem 0;
}

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

.section-title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-color);
    font-weight: 700;
}

/* About Section */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
}

.about-content p {
    margin-bottom: 1.5rem;
}

/* Research Section */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.research-card {
    background-color: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

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

.research-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.research-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.research-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    background-color: white;
    padding: 2rem;
    border-radius: 1rem;
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
}

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

.project-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.project-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s ease;
}

.project-link:hover {
    gap: 0.75rem;
}

/* Publications Section */
.publications-intro {
    text-align: center;
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    color: var(--text-light);
}

.publications-link {
    text-align: center;
    margin-top: 3rem;
}

.publications-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin: 3rem 0;
}

.publications-subsection {
    background-color: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
}

.subsection-title {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.subsection-title i {
    color: var(--primary-color);
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.publication-item {
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.publication-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.publication-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.5rem;
    line-height: 1.4;
    display: block;
    text-decoration: none;
    transition: color 0.3s ease;
}

.publication-title:hover {
    color: var(--primary-color);
}

.publication-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.publication-venue {
    color: var(--text-color);
    font-style: italic;
}

.publication-citations {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    color: var(--primary-color);
    font-weight: 600;
}

.publication-citations i {
    font-size: 0.8rem;
}

.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-light);
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    max-width: 900px;
    margin: 0 auto;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
}

.contact-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-top: 0.25rem;
}

.contact-item h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.contact-item p {
    color: var(--text-light);
    line-height: 1.6;
}

.contact-item p a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-item p a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.contact-social h4 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.social-links-large {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.social-btn {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background-color: var(--bg-alt);
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    transition: all 0.3s ease;
}

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

.social-btn i {
    font-size: 1.5rem;
}

/* Footer */
.footer {
    background-color: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-image {
        display: flex;
        justify-content: center;
    }

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

    .subtitle {
        font-size: 1.2rem;
    }

    .nav-menu {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .social-links,
    .cv-links {
        justify-content: center;
    }

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

    .contact-content {
        grid-template-columns: 1fr;
    }

    .social-links-large {
        grid-template-columns: 1fr;
    }

    .publications-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .nav-menu {
        display: none;
    }

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

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

    .cv-links {
        flex-direction: column;
        width: 100%;
    }

    .cv-links .btn {
        width: 100%;
        justify-content: center;
    }
}