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

html {
    scroll-behavior: smooth;
}

:root {
    /* Light theme (default) */
    --bg-primary: #fff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #333;
    --text-secondary: #555;
    --text-muted: #666;
    --accent-color: #3498db;
    --accent-hover: #2980b9;
    --border-color: #e0e0e0;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(0, 0, 0, 0.15);
    --navbar-bg: rgba(255, 255, 255, 0.95);
    --card-bg: #fff;
    --input-bg: #fff;
    --input-border: #e0e0e0;
}



body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--navbar-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease, transform 0.3s ease;
    transform: translateY(0);
}

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


.nav-logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-logo a:hover {
    color: var(--accent-color);
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--accent-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: var(--accent-color);
    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 {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

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

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

.hero-right {
    text-align: left;
}

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

.profile-photo {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.profile-photo:hover {
    transform: scale(1.05);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #fff, #e8f4fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 2rem;
    opacity: 0.9;
    color: rgba(255, 255, 255, 0.9);
}

.hero-description {
    font-size: 1.1rem;
    max-width: 800px;
    margin: 0 auto 3rem;
    opacity: 0.9;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.9);
}

.hero-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-secondary {
    padding: 12px;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-primary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border-color: rgba(255, 255, 255, 0.3);
}

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

.btn-secondary {
    background: transparent;
    color: white;
    border-color: rgba(255, 255, 255, 0.5);
    padding: 12px;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.8);
    transform: translateY(-2px);
}

/* LinkedIn specific styling */
.btn-secondary .fab.fa-linkedin {
    color: #0077b5;
}

.btn-secondary:hover .fab.fa-linkedin {
    color: #005885;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    width: 60px;
    height: 4px;
    background: linear-gradient(45deg, #3498db, #2980b9);
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

/* About Section */
.about {
    background: var(--bg-secondary);
}

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

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* News Section */
.news {
    background: var(--bg-primary);
}

.news-year-selector {
    text-align: center;
    margin-bottom: 3rem;
}

.year-dropdown {
    padding: 12px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 50px;
    background: white;
    font-size: 1rem;
    font-weight: 500;
    color: #555;
    cursor: pointer;
    transition: all 0.3s ease;
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 12px center;
    background-repeat: no-repeat;
    background-size: 16px;
    padding-right: 40px;
    min-width: 150px;
}

.year-dropdown:hover {
    border-color: #3498db;
    background-color: rgba(52, 152, 219, 0.05);
}

.year-dropdown:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.news-timeline {
    max-width: 960px; /* 1.2x increase from 800px */
    margin: 0 auto;
    position: relative;
}

.scrollable-news {
    max-height: 525px; /* 1.5x increase from 350px */
    overflow-y: scroll;
    padding-right: 20px;
    /* Custom scrollbar */
    scrollbar-width: auto;
    scrollbar-color: var(--accent-color) var(--bg-secondary);
    /* Box styling with increased size */
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    background: var(--card-bg);
    box-shadow: 0 2px 10px var(--shadow);
}

.scrollable-news::-webkit-scrollbar {
    width: 14px;
    background: var(--bg-secondary);
}

.scrollable-news::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 7px;
    border: 1px solid var(--border-color);
}

.scrollable-news::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 7px;
    border: 2px solid var(--bg-secondary);
    min-height: 20px;
    transition: all 0.3s ease;
}

.scrollable-news::-webkit-scrollbar-thumb:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
}

.scrollable-news::-webkit-scrollbar-thumb:active {
    background: var(--accent-hover);
}

.scrollable-news::-webkit-scrollbar-corner {
    background: var(--bg-secondary);
}


.news-item {
    position: relative;
    margin-bottom: 2rem;
    padding-left: 60px;
    z-index: 2;
}

.news-item::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 8px;
    width: 12px;
    height: 12px;
    background-color: var(--accent-color);
    border-radius: 50%;
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 2px var(--accent-color);
    z-index: 3;
}


.news-date {
    font-weight: 600;
    color: var(--accent-color);
    font-size: 0.8rem;
    margin-bottom: 0.5rem;
}

.news-content {
    color: var(--text-secondary);
    line-height: 1.5;
    font-size: 0.9rem;
}

.news-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
}

.news-link:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* News item visibility */
.news-item {
    transition: opacity 0.3s ease, transform 0.3s ease;
    display: block;
}

.news-item.hidden {
    display: none !important;
    opacity: 0;
    transform: translateY(-10px);
    pointer-events: none;
    visibility: hidden;
}

/* Publications Section */
.publications {
    background: #f8f9fa;
}

.publications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.publication-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.publication-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.publication-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.publication-authors {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.publication-venue {
    color: #3498db;
    font-weight: 500;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

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

.publication-link {
    color: #3498db;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

.publication-link:hover {
    color: #2980b9;
    text-decoration: underline;
}

/* Teaching Section */
.teaching {
    background: white;
}

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

.teaching-item {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    border-left: 4px solid #3498db;
}

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

.teaching-item p {
    color: #666;
    line-height: 1.6;
}

/* Scholarships Section */
.scholarships {
    background: #f8f9fa;
}

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

.scholarship-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    border-left: 4px solid #e74c3c;
}

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

.scholarship-item p {
    color: #666;
    line-height: 1.6;
}

/* Contact Section */
.contact {
    background: #f8f9fa;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    max-width: 1200px;
    margin: 0 auto;
}

.contact-info {
    text-align: center;
}

.contact-form-container {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
    padding: 12px 16px;
    border: 2px solid var(--input-border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    font-family: inherit;
    background-color: var(--input-bg);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}


.contact-form button[type="submit"] {
    background: linear-gradient(45deg, #3498db, #2980b9) !important;
    color: white !important;
    border: none !important;
    padding: 12px 24px !important;
    border-radius: 50px !important;
    font-size: 1rem !important;
    font-weight: 500 !important;
    cursor: pointer !important;
    transition: all 0.3s ease !important;
    display: flex !important;
    align-items: center !important;
    gap: 0.5rem !important;
    justify-content: center !important;
    width: 100% !important;
    margin-top: 1rem !important;
    visibility: visible !important;
    opacity: 1 !important;
}

.contact-form button[type="submit"]:hover {
    background: linear-gradient(45deg, #2980b9, #1f5f8b);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
}

.contact-form button[type="submit"]:active {
    transform: translateY(0);
}

.form-status {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.form-status.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.form-status.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.contact-email {
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

.contact-email i {
    margin-right: 0.5rem;
    color: #3498db;
}

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

.contact-email a:hover {
    color: #3498db;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    color: #555;
    text-decoration: none;
    padding: 12px;
    border-radius: 50%;
    border: 2px solid #e0e0e0;
    transition: all 0.3s ease;
    font-weight: 500;
    width: 48px;
    height: 48px;
}

.social-link:hover {
    color: #3498db;
    border-color: #3498db;
    background: rgba(52, 152, 219, 0.1);
    transform: translateY(-2px);
}

/* LinkedIn color in contact section */
.social-link .fab.fa-linkedin {
    color: #0077b5;
}

.social-link:hover .fab.fa-linkedin {
    color: #005885;
}

/* X (formerly Twitter) color styling - make it black */
.btn-secondary span[style*="font-weight: bold"],
.social-link span[style*="font-weight: bold"],
a[href*="x.com"] span[style*="font-weight: bold"],
a[href*="twitter.com"] span[style*="font-weight: bold"],
span[style*="font-weight: bold"] {
    color: #000000 !important;
}

.btn-secondary:hover span[style*="font-weight: bold"],
.social-link:hover span[style*="font-weight: bold"],
a[href*="x.com"]:hover span[style*="font-weight: bold"],
a[href*="twitter.com"]:hover span[style*="font-weight: bold"],
span[style*="font-weight: bold"]:hover {
    color: #000000 !important;
}

/* Footer */
.footer {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    text-align: center;
    padding: 2rem 0;
}

.footer p {
    opacity: 0.8;
}

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

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

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

    .nav-item {
        margin: 1rem 0;
    }

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

    .hero-right {
        text-align: center;
    }

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

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-links {
        flex-direction: row;
        align-items: center;
        justify-content: center;
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .profile-photo {
        width: 240px;
        height: 240px;
    }

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

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

    .social-links {
        flex-direction: row;
        align-items: center;
        justify-content: center;
        flex-wrap: wrap;
        gap: 1rem;
    }

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

    .news-item {
        padding-left: 40px;
    }
    
    .news-item::before {
        left: 15px;
    }



    .profile-photo {
        width: 300px;
        height: 300px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 100px 0 60px;
    }

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

    section {
        padding: 60px 0;
    }

    .publication-item,
    .teaching-item,
    .scholarship-item {
        padding: 1.5rem;
    }

    .profile-photo {
        width: 200px;
        height: 200px;
    }
    
    
    /* Mobile scroll to top button */
    .scroll-to-top {
        bottom: 15px !important;
        left: 15px !important;
        width: 45px !important;
        height: 45px !important;
        font-size: 16px !important;
    }
}

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

.news-item,
.publication-item,
.teaching-item,
.scholarship-item {
    animation: fadeInUp 0.6s ease-out;
}

/* Smooth scrolling for anchor links */
html {
    scroll-behavior: smooth;
}

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

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