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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* Navigation */
.navbar {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.nav-logo h2 {
    color: #2c3e50;
    font-weight: 600;
    font-size: 1.5rem;
}

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

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

.nav-link:hover {
    color: #2c3e50;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: #2c3e50;
    transition: width 0.3s ease;
}

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

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

.bar {
    width: 25px;
    height: 3px;
    background-color: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
    padding: 120px 0 80px;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.8rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: #e8f4fd;
}

.hero-institution {
    font-size: 1.4rem;
    font-weight: 400;
    margin-bottom: 2rem;
    color: #b8d4f0;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
    line-height: 1.7;
    color: #f0f8ff;
}

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

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: #fff;
    color: #2c3e50;
}

.btn-primary:hover {
    background: #f8f9fa;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: transparent;
    color: #fff;
    border: 2px solid #fff;
}

.btn-secondary:hover {
    background: #fff;
    color: #2c3e50;
    transform: translateY(-2px);
}

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

.profile-image {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
    border: 4px solid rgba(255,255,255,0.3);
    backdrop-filter: blur(10px);
    transition: transform 0.3s ease;
}

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

.profile-photo {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

/* Section Styles */
section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 3rem;
    color: #2c3e50;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    width: 60px;
    height: 4px;
    background: #2c3e50;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
}

/* About Section */
.about {
    background: #f8f9fa;
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: #555;
    line-height: 1.8;
}

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

.stat-item {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-5px);
}

.stat-item h3 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.stat-item p {
    color: #666;
    font-weight: 500;
}

/* Education Section */
.education {
    background: white;
}

.education-timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.education-timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: #2c3e50;
    transform: translateX(-50%);
}

.timeline-item {
    display: flex;
    margin-bottom: 3rem;
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-marker {
    width: 20px;
    height: 20px;
    background: #2c3e50;
    border-radius: 50%;
    position: absolute;
    left: 50%;
    top: 20px;
    transform: translateX(-50%);
    z-index: 2;
    border: 4px solid white;
    box-shadow: 0 0 0 4px #2c3e50;
}

.timeline-content {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    width: 45%;
    position: relative;
}

.timeline-content h3 {
    color: #2c3e50;
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

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

.timeline-content .institution {
    font-weight: 600;
    color: #555;
    margin-bottom: 0.3rem;
}

.timeline-content .duration {
    color: #888;
    font-style: italic;
}

/* Research Section */
.research {
    background: #f8f9fa;
}

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

.research-card {
    background: white;
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    text-align: center;
    transition: all 0.3s ease;
    border-top: 4px solid #2c3e50;
}

.research-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

.research-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #2c3e50, #34495e);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.research-icon i {
    font-size: 2rem;
    color: white;
}

.research-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.research-card p {
    color: #666;
    line-height: 1.6;
}

/* Publications Section */
.publications {
    background: white;
}

.publications-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-bottom: 3rem;
}

.publications-stats,
.publications-journals {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 10px;
}

.publications-stats h3,
.publications-journals h3 {
    color: #2c3e50;
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

.publications-stats ul,
.publications-journals ul {
    list-style: none;
}

.publications-stats li,
.publications-journals li {
    padding: 0.5rem 0;
    color: #555;
    border-bottom: 1px solid #e9ecef;
}

.publications-stats li:last-child,
.publications-journals li:last-child {
    border-bottom: none;
}

.publications-stats strong {
    color: #2c3e50;
}

.publications-note {
    text-align: center;
    font-style: italic;
    color: #666;
}

.publications-note a {
    color: #2c3e50;
    text-decoration: none;
    font-weight: 500;
}

.publications-note a:hover {
    text-decoration: underline;
}

/* Recent Publications */
.recent-publications {
    margin-top: 3rem;
}

.recent-publications h3 {
    color: #2c3e50;
    margin-bottom: 2rem;
    font-size: 1.5rem;
    text-align: center;
}

.publications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.publication-item {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    border-left: 4px solid #2c3e50;
    transition: all 0.3s ease;
}

.publication-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

.publication-item h4 {
    color: #2c3e50;
    font-size: 1.1rem;
    margin-bottom: 0.8rem;
    line-height: 1.4;
}

.publication-authors {
    color: #2c3e50;
    font-weight: 500;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.publication-journal {
    color: #666;
    font-style: italic;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.publication-abstract {
    color: #555;
    line-height: 1.6;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.publication-link {
    display: inline-block;
    background: #2c3e50;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

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

/* Publications Timeline */
.publications-timeline {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 10px;
    margin-top: 2rem;
}

.publications-timeline h3 {
    color: #2c3e50;
    margin-bottom: 1.5rem;
    text-align: center;
    font-size: 1.3rem;
}

.timeline-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.year-stat {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.year-stat:hover {
    transform: translateY(-3px);
}

.year-stat .year {
    display: block;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.year-stat .count {
    display: block;
    color: #2c3e50;
    font-size: 1.2rem;
    font-weight: 700;
}


/* Footer */
.footer {
    background: #2c3e50;
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    color: #ecf0f1;
}

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

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

.footer-section ul li a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ecf0f1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #34495e;
    color: #bdc3c7;
}

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

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

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

    .nav-menu li {
        margin: 1rem 0;
    }

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

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

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

    .about-stats {
        flex-direction: row;
        justify-content: space-around;
    }

    .education-timeline::before {
        left: 20px;
    }

    .timeline-item {
        flex-direction: row !important;
        padding-left: 3rem;
    }

    .timeline-marker {
        left: 20px;
        transform: translateX(-50%);
    }

    .timeline-content {
        width: 100%;
    }

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

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


    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 200px;
    }

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

    .timeline-stats {
        grid-template-columns: 1fr;
    }

    .profile-image {
        width: 250px;
        height: 250px;
    }
}

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

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

    .about-stats {
        flex-direction: column;
    }

    .stat-item {
        padding: 1.5rem;
    }

    .profile-image {
        width: 200px;
        height: 200px;
    }

    .publication-item {
        padding: 1.5rem;
    }
}

/* Smooth scrolling and animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Loading states */
.loading {
    opacity: 0.7;
    pointer-events: none;
}

/* Focus states for accessibility */
.btn:focus,
.nav-link:focus,
input:focus,
textarea:focus {
    outline: 2px solid #3498db;
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .navbar,
    .hero-buttons,
    .contact-form,
    .footer {
        display: none;
    }
    
    .hero {
        background: white;
        color: black;
    }
    
    section {
        page-break-inside: avoid;
    }
}