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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid #e1e1e1;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    height: 70px;
}

.nav-logo a {
    font-size: 1.5rem;
    font-weight: 600;
    text-decoration: none;
    color: #2c3e50;
    transition: color 0.3s ease;
}

.nav-logo a:hover {
    color: #3498db;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #3498db;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: #3498db;
    transition: width 0.3s ease;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    font-size: 1.2rem;
}

/* Hero Sections - General Styles */
.publications-hero,
.experience-hero,
.teaching-hero,
.contact-hero,
.achievements-hero,
.research-hero {
    margin-top: 70px;
    padding: 60px 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    color: #333 !important;
    text-align: center;
}

.publications-hero h1,
.experience-hero h1,
.teaching-hero h1,
.contact-hero h1,
.achievements-hero h1,
.research-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #2c3e50 !important;
    font-weight: 700;
}

.publications-hero p,
.experience-hero p,
.teaching-hero p,
.contact-hero p,
.achievements-hero p,
.research-hero p {
    font-size: 1.2rem;
    color: #555 !important;
}

/* Hero Section */
.hero {
    margin-top: 70px;
    padding: 80px 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    color: #333 !important;
}

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

.hero-image {
    position: relative;
}

.profile-img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.profile-img:hover {
    transform: scale(1.05);
}

.hero-text h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2c3e50 !important;
    margin-bottom: 0.5rem;
}

.hero-text h2 {
    font-size: 1.3rem;
    font-weight: 500;
    color: #3498db;
    margin-bottom: 1rem;
}

.institution {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.4;
}

.institution a {
    color: #3498db;
    text-decoration: none;
}

.institution a:hover {
    text-decoration: underline;
}

.research-areas {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.tag {
    background: #3498db;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

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

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 45px;
    height: 45px;
    background: #fff;
    color: #333;
    border-radius: 50%;
    text-decoration: none;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    font-size: 1.2rem;
}

.social-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.social-link:nth-child(1):hover { color: #e74c3c; } /* Email */
.social-link:nth-child(2):hover { color: #4285f4; } /* Scholar */
.social-link:nth-child(3):hover { color: #0077b5; } /* LinkedIn */
.social-link:nth-child(4):hover { color: #333; } /* GitHub */
.social-link:nth-child(5):hover { color: #a6ce39; } /* ORCID */

/* News Section */
.news-section {
    padding: 3rem 0;
    background: #fff;
    border-bottom: 1px solid #e1e1e1;
}

.news-container h3 {
    color: #2c3e50;
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.news-container h3 i {
    color: #3498db;
}

.news-items {
    display: grid;
    gap: 1rem;
}

.news-item {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 1rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.news-item:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.news-item.highlight {
    background: linear-gradient(135deg, #e3f2fd 0%, #f3e5f5 100%);
    border-left: 4px solid #3498db;
}

.news-date {
    font-weight: 600;
    color: #3498db;
    font-size: 0.9rem;
}

.news-content {
    color: #555;
}

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

section:nth-child(even) {
    background: #f8f9fa;
}

h2 {
    font-size: 2rem;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 2rem;
    text-align: center;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: #3498db;
    border-radius: 2px;
}

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    line-height: 1.7;
    color: #555;
}

.about-text a {
    color: #3498db;
    text-decoration: none;
}

.about-text a:hover {
    text-decoration: underline;
}

.supervisors h3 {
    font-size: 1.3rem;
    color: #2c3e50;
    margin-bottom: 1rem;
}

.supervisor-cards {
    display: grid;
    gap: 1rem;
}

.supervisor-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
    text-align: center;
}

.supervisor-card:hover {
    transform: translateY(-5px);
}

.supervisor-img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1rem;
    border: 3px solid #3498db;
}

.supervisor-card h4 {
    font-size: 1.1rem;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.supervisor-card p {
    color: #666;
    margin: 0.25rem 0;
}

/* Research Interests */
.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.interest-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.interest-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.interest-card i {
    font-size: 2.5rem;
    color: #3498db;
    margin-bottom: 1rem;
}

.interest-card h3 {
    font-size: 1.2rem;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.interest-card p {
    color: #666;
    font-size: 0.95rem;
}

/* Education Timeline */
.education-timeline {
    max-width: 800px;
    margin: 0 auto;
}

.education-item {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 2rem;
    padding: 2rem 0;
    border-left: 2px solid #3498db;
    position: relative;
    margin-left: 2rem;
}

.education-item::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 2.5rem;
    width: 12px;
    height: 12px;
    background: #3498db;
    border-radius: 50%;
    box-shadow: 0 0 0 4px white;
}

.education-date {
    font-weight: 600;
    color: #3498db;
    font-size: 0.95rem;
}

.education-content h3 {
    font-size: 1.2rem;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.education-content p {
    color: #666;
    margin: 0.25rem 0;
}

/* Publications */
.publications-grid {
    display: grid;
    gap: 2rem;
    margin-bottom: 2rem;
}

.publication-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.publication-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.publication-card h3 {
    font-size: 1.2rem;
    color: #2c3e50;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.authors {
    color: #666;
    margin-bottom: 0.5rem;
}

.venue {
    color: #3498db;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.status {
    color: #e67e22;
    font-style: italic;
    margin-bottom: 1rem;
}

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

.publication-links a {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.9rem;
    transition: background 0.3s ease;
}

.publication-links a:hover {
    background: #2980b9;
}

.view-all {
    text-align: center;
}

.btn-primary {
    display: inline-block;
    padding: 0.75rem 2rem;
    background: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-2px);
}

/* Citation Modal Styles */
.cite-btn {
    background: #2c3e50;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-left: 0.5rem;
}

.cite-btn:hover {
    background: #34495e;
    transform: translateY(-2px);
}

.citation-modal {
    display: none;
    position: fixed;
    z-index: 10000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.3s ease;
}

.citation-modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 2rem;
    border-radius: 8px;
    width: 90%;
    max-width: 800px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    animation: slideIn 0.3s ease;
}

.citation-close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    top: 15px;
    right: 25px;
}

.citation-close:hover {
    color: #333;
}

.citation-title {
    margin-bottom: 1rem;
    color: #2c3e50;
    font-size: 1.3rem;
}

.bibtex-content {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 4px;
    padding: 1rem;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-all;
    overflow-x: auto;
}

.copy-citation-btn {
    background: #3498db;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    margin-top: 1rem;
    transition: background 0.3s ease;
}

.copy-citation-btn:hover {
    background: #2980b9;
}

.copy-citation-btn.copied {
    background: #27ae60;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* Footer Styles */
.footer {
    background: #2c3e50;
    color: white;
    padding: 3rem 0 2rem;
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-info p {
    margin: 0.5rem 0;
    opacity: 0.9;
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.footer-links a {
    color: white;
    text-decoration: none;
    opacity: 0.9;
    transition: opacity 0.3s ease;
    font-size: 0.9rem;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: 2rem 0;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
    }

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

    .nav-toggle {
        display: block;
    }

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

    .profile-img {
        width: 150px;
        height: 150px;
    }

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

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

    .education-item {
        grid-template-columns: 1fr;
        gap: 1rem;
        margin-left: 1rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .footer-links {
        flex-direction: column;
        gap: 1rem;
    }

    .news-item {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 40px 0;
    }

    .hero-text h1 {
        font-size: 1.8rem;
    }

    .research-areas {
        justify-content: center;
    }

    .tag {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }

    section {
        padding: 3rem 0;
    }

    h2 {
        font-size: 1.6rem;
    }

    .container {
        padding: 0 15px;
    }
}