/* CSS Variables for Theme Support */
:root {
    /* Light Theme Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --shadow-light: rgba(0, 0, 0, 0.1);
    --shadow-medium: rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
}

/* Dark Theme Colors */
.dark-theme {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --accent-color: #60a5fa;
    --accent-hover: #3b82f6;
    --shadow-light: rgba(0, 0, 0, 0.3);
    --shadow-medium: rgba(0, 0, 0, 0.4);
}

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

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-family);
    line-height: var(--line-height-base);
    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 var(--spacing-lg);
}

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

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

.nav-logo h2 {
    color: var(--accent-color);
    font-weight: 700;
    font-size: 1.5rem;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
    font-size: 0.95rem;
}

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

.nav-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--bg-secondary);
    color: var(--accent-color);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* Main Content */
.main-content {
    margin-top: 70px;
    min-height: calc(100vh - 70px);
}

/* Home Section */
.home-section {
    padding: var(--spacing-2xl) 0;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xl);
    color: var(--text-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-2xl);
    align-items: start;
}

.about-text p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
    font-size: 1.1rem;
    line-height: 1.7;
}

.contact-info {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
}

.contact-info p {
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.profile-image {
    text-align: center;
}

.profile-img {
    width: 100%;
    max-width: 300px;
    height: 300px;
    object-fit: cover;
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 30px var(--shadow-light);
}

/* Section Styles */
.section {
    padding: var(--spacing-2xl) 0;
    border-bottom: 1px solid var(--border-color);
}

.section:last-child {
    border-bottom: none;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xl);
    color: var(--text-primary);
}

/* Publications Section */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.publication-item {
    display: flex;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
    transition: all 0.3s ease;
}

.publication-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--shadow-light);
}

.publication-year {
    min-width: 80px;
    font-weight: 600;
    color: var(--accent-color);
    font-size: 1.1rem;
}

.publication-content {
    flex: 1;
}

.publication-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.journal-badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
}

.journal-badge.q1 {
    background-color: #10b981;
    color: white;
}

.publication-date {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.publication-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.authors {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-size: 0.95rem;
}

.journal-name {
    color: var(--accent-color);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
    font-style: italic;
}

.publication-abstract {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.publication-links {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.publication-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 6px 12px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.publication-link:hover {
    background-color: var(--accent-color);
    color: white;
}

/* News Section */
.news-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.news-item {
    display: flex;
    gap: var(--spacing-lg);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}

.news-item:hover {
    background-color: var(--bg-tertiary);
}

.news-date {
    min-width: 100px;
    font-weight: 600;
    color: var(--accent-color);
    font-size: 0.9rem;
}

.news-content {
    flex: 1;
}

.news-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.news-toggle {
    margin-top: var(--spacing-lg);
    text-align: center;
}

.toggle-btn {
    background: none;
    border: none;
    color: var(--accent-color);
    cursor: pointer;
    font-size: 1rem;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin: 0 auto;
}

.toggle-btn:hover {
    background-color: var(--bg-secondary);
}

.toggle-btn i {
    transition: transform 0.3s ease;
}

.older-news {
    margin-top: var(--spacing-lg);
}

/* Awards & Scholarships Section */
.awards-list,
.scholarships-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.award-item,
.scholarship-item {
    display: flex;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
    transition: all 0.3s ease;
}

.award-item:hover,
.scholarship-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--shadow-light);
}

.award-year,
.scholarship-year {
    width: 120px;
    font-weight: 600;
    color: var(--accent-color);
    font-size: 1.1rem;
}

.award-content {
    flex: 1;
}

.award-content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.award-institution {
    color: var(--accent-color);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    font-size: 0.95rem;
}

.award-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Experience Section */
.experience-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.experience-item {
    display: flex;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
}

.experience-period {
    min-width: 120px;
    font-weight: 600;
    color: var(--accent-color);
    font-size: 1rem;
}

.experience-content {
    flex: 1;
}

.experience-content h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.institution {
    color: var(--accent-color);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.supervisor {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-sm);
}

.responsibilities {
    list-style: none;
}

.responsibilities li {
    padding: var(--spacing-xs) 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: var(--spacing-md);
}

.responsibilities li::before {
    content: '▶';
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-size: 0.8rem;
}

/* Projects Section */
.projects-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.project-item {
    padding: var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
    transition: all 0.3s ease;
}

.project-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--shadow-light);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.project-header h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
}

.project-links {
    display: flex;
    gap: var(--spacing-sm);
}

.project-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 6px 12px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.project-link:hover {
    background-color: var(--accent-color);
    color: white;
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tech-tag {
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

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

.footer-section h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--accent-color);
}

.footer-section p {
    margin-bottom: var(--spacing-xs);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-link:hover {
    background-color: var(--accent-color);
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .nav-container {
        padding: 0 var(--spacing-md);
    }

    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-primary);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px var(--shadow-light);
        padding: var(--spacing-lg) 0;
        border-bottom: 1px solid var(--border-color);
    }

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

    .nav-menu a {
        padding: var(--spacing-sm) 0;
        border-bottom: 1px solid var(--border-color);
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--spacing-lg);
    }

    .page-title {
        font-size: 2rem;
    }
    
    .publication-item,
    .experience-item,
    .news-item,
    .award-item,
    .scholarship-item {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .publication-year,
    .experience-period,
    .news-date,
    .award-year,
    .scholarship-year {
        width: auto;
        font-size: 0.9rem;
    }

    .project-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .section {
        padding: var(--spacing-xl) 0;
    }

    .section-title {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .nav-container {
        padding: 0 var(--spacing-sm);
    }

    .page-title {
        font-size: 1.8rem;
    }

    .publication-item,
    .experience-item,
    .project-item,
    .news-item,
    .award-item,
    .scholarship-item {
        padding: var(--spacing-md);
    }

    .section {
        padding: var(--spacing-lg) 0;
    }

    .publication-links,
    .project-links {
        flex-direction: column;
    }
}

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

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

/* Scroll animations */
.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.scroll-animate.animate {
    opacity: 1;
    transform: translateY(0);
}

/* BibTeX Inline Styles */
.bibtex-section {
    margin-top: 1rem;
    padding: 1.5rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        max-height: 0;
        padding-top: 0;
        padding-bottom: 0;
    }
    to {
        opacity: 1;
        max-height: 500px;
        padding-top: 1.5rem;
        padding-bottom: 1.5rem;
    }
}

.bibtex-content {
    width: 100%;
}

.bibtex-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.bibtex-header h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.bibtex-code {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 1rem;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    line-height: 1.4;
    color: var(--text-primary);
    white-space: pre-wrap;
    word-wrap: break-word;
    overflow-x: auto;
    margin-bottom: 0;
}

.bibtex-copy-btn {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 500;
    font-size: 0.85rem;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.bibtex-copy-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

.bibtex-copy-btn.copied {
    background-color: #10b981;
}

.bibtex-toggle {
    position: relative;
    transition: all 0.2s ease;
}

.bibtex-toggle.active {
    color: var(--accent-color) !important;
}

.bibtex-toggle.active i {
    transform: rotate(180deg);
    transition: transform 0.3s ease;
}

/* Responsive Design */
@media (max-width: 768px) {
    .bibtex-section {
        padding: 1rem;
    }
    
    .bibtex-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .bibtex-copy-btn {
        align-self: flex-end;
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
    
    .bibtex-code {
        font-size: 0.75rem;
        padding: 0.75rem;
    }
}

/* Print styles */
@media print {
    .navbar,
    .theme-toggle,
    .hamburger,
    .footer,
    .bibtex-copy-btn {
        display: none !important;
    }
    
    .main-content {
        margin-top: 0;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .bibtex-section {
        border: 1px solid #ccc;
        background: white !important;
    }
}

/* Connect Section in About Me - Consistent Design */
.connect-section {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent-color);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    transition: all 0.3s ease;
}

.connect-section:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--shadow-light);
}

.connect-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.connect-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.connect-header p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin: 0;
}

.social-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    text-decoration: none;
    color: white;
    font-size: 1.25rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px var(--shadow-light);
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: 50%;
    background: inherit;
    transition: transform 0.3s ease;
}

.social-link:hover::before {
    transform: scale(1.1);
}

.social-link i {
    position: relative;
    z-index: 1;
}

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

/* Individual platform colors */
.social-link.linkedin {
    background: #0077b5;
}

.social-link.linkedin:hover {
    background: #005885;
}

.social-link.github {
    background: #333;
}

.social-link.github:hover {
    background: #000;
}

.social-link.scholar {
    background: #4285f4;
}

.social-link.scholar:hover {
    background: #1a73e8;
}

.social-link.facebook {
    background: #1877f2;
}

.social-link.facebook:hover {
    background: #0d5bb8;
}

.social-link.email {
    background: #ea4335;
}

.social-link.email:hover {
    background: #d33b2c;
}

/* Responsive Design for Connect Section */
@media (max-width: 768px) {
    .connect-section {
        margin-top: var(--spacing-lg);
        padding: var(--spacing-md);
        max-width: 100%;
    }
    
    .connect-header h3 {
        font-size: 1.25rem;
    }
    
    .connect-header p {
        font-size: 0.9rem;
    }
    
    .social-links {
        gap: var(--spacing-sm);
    }
    
    .social-link {
        width: 45px;
        height: 45px;
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .connect-section {
        margin-top: var(--spacing-md);
        padding: var(--spacing-sm);
        max-width: 100%;
    }
    
    .connect-header h3 {
        font-size: 1.1rem;
    }
    
    .connect-header p {
        font-size: 0.85rem;
    }
    
    .social-links {
        gap: var(--spacing-xs);
    }
    
    .social-link {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
}