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

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --shadow-light: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-medium: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-large: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    --font-size-6xl: 3.75rem;
    
    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-5: 1.25rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-10: 2.5rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    --spacing-24: 6rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-base: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-base: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
}

/* Dark mode support */
[data-theme="dark"] {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-light: #94a3b8;
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --border-color: #475569;
    --shadow-light: 0 1px 3px 0 rgb(0 0 0 / 0.3), 0 1px 2px -1px rgb(0 0 0 / 0.3);
    --shadow-medium: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --shadow-large: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
}

/* Auto dark mode based on system preference */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --primary-color: #3b82f6;
        --primary-dark: #2563eb;
        --text-primary: #f8fafc;
        --text-secondary: #cbd5e1;
        --text-light: #94a3b8;
        --bg-primary: #0f172a;
        --bg-secondary: #1e293b;
        --bg-tertiary: #334155;
        --border-color: #475569;
        --shadow-light: 0 1px 3px 0 rgb(0 0 0 / 0.3), 0 1px 2px -1px rgb(0 0 0 / 0.3);
        --shadow-medium: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
        --shadow-large: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
        --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
    }
}

/* Base Styles */
html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

/* Section */
.section {
    padding: var(--spacing-20) 0;
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-8);
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -var(--spacing-2);
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-full);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-4);
    font-style: italic;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: var(--spacing-4) 0;
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
    opacity: 0.95;
}

.navbar.scrolled {
    background: var(--bg-primary);
    box-shadow: var(--shadow-medium);
    opacity: 0.98;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo a {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-8);
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width var(--transition-base);
}

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

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger .bar {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: all var(--transition-base);
    border-radius: var(--radius-full);
}

.hamburger.active .bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

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

.hamburger.active .bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
    position: relative;
    z-index: 2;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: center;
}

.hero-text {
    order: 1;
}

.hero-image {
    order: 2;
}

.greeting {
    display: block;
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: var(--spacing-2);
}

.name {
    display: block;
    font-size: var(--font-size-6xl);
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.1;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--font-size-2xl);
    color: var(--text-secondary);
    margin: var(--spacing-4) 0;
    font-weight: 500;
}

.hero-description {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-8);
    line-height: 1.7;
}

.hero-description p {
    margin-bottom: var(--spacing-4);
}

.hero-description a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-base);
}

.hero-description a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* Research Interests */
.research-interests {
    margin-bottom: var(--spacing-6);
}

.research-interests h4 {
    font-size: var(--font-size-base);
    color: var(--text-primary);
    margin-bottom: var(--spacing-3);
    font-weight: 600;
}

.interest-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-2);
}

.interest-tag {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: var(--spacing-2) var(--spacing-3);
    border-radius: var(--radius-base);
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: all var(--transition-base);
}

.interest-tag:hover {
    background: var(--bg-primary);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
}

/* Contact Email */
.contact-email {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    color: var(--text-secondary);
    font-size: var(--font-size-base);
    margin-top: var(--spacing-4);
    padding: var(--spacing-3) var(--spacing-4);
    background: var(--bg-secondary);
    border-radius: var(--radius-base);
    border: 1px solid var(--border-color);
}

.contact-email i {
    color: var(--primary-color);
    font-size: var(--font-size-lg);
}

.contact-email span {
    font-family: 'Courier New', monospace;
    font-weight: 500;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-8);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-2);
    padding: var(--spacing-3) var(--spacing-6);
    border-radius: var(--radius-lg);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    font-size: var(--font-size-base);
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-large);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

.social-links {
    display: flex;
    gap: var(--spacing-4);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: var(--radius-full);
    text-decoration: none;
    transition: all var(--transition-base);
    font-size: var(--font-size-lg);
}

.social-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.image-container {
    position: relative;
    display: flex;
    justify-content: center;
}

.profile-image {
    width: 300px;
    height: 300px;
    border-radius: var(--radius-2xl);
    object-fit: cover;
    border: 4px solid white;
    box-shadow: var(--shadow-xl);
    position: relative;
    z-index: 2;
}

.image-decoration {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-2xl);
    z-index: 1;
}

/* Floating Shapes Animation */
.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    z-index: 1;
}

.floating-shapes {
    position: relative;
    width: 100%;
    height: 100%;
}

.shape {
    position: absolute;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-full);
    animation: float 6s ease-in-out infinite;
    opacity: 0.1;
}

.shape-1 {
    width: 80px;
    height: 80px;
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 60px;
    height: 60px;
    top: 60%;
    right: 10%;
    animation-delay: 2s;
}

.shape-3 {
    width: 100px;
    height: 100px;
    top: 80%;
    left: 20%;
    animation-delay: 4s;
}

.shape-4 {
    width: 40px;
    height: 40px;
    top: 30%;
    right: 30%;
    animation-delay: 1s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}



/* Education Section */
.education-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-6);
    max-width: 900px;
    margin: 0 auto;
}

.education-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-medium);
    padding: var(--spacing-8);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    display: flex;
    gap: var(--spacing-6);
    align-items: center;
}

.education-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.education-logo {
    flex-shrink: 0;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-3);
}

.university-logo {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.education-content {
    flex: 1;
}

.education-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-3);
    flex-wrap: wrap;
    gap: var(--spacing-2);
}

.education-header h3 {
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    margin: 0;
    line-height: 1.3;
}

.education-date {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: var(--spacing-2) var(--spacing-4);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    white-space: nowrap;
}

.education-institution {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: var(--spacing-1);
}

.education-department {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2);
}

.education-supervisor {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-3);
    font-size: var(--font-size-sm);
    font-style: italic;
}

.education-supervisor a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.education-supervisor a:hover {
    text-decoration: underline;
}

.education-details {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.education-status {
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.education-status.current {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
}

.education-status.completed {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
}

.thesis-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-1);
    color: var(--primary-color);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    padding: var(--spacing-2) var(--spacing-3);
    border: 1px solid var(--primary-color);
    border-radius: var(--radius-base);
    transition: all var(--transition-base);
}

.thesis-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
}

/* Experience Section */
.experience-section {
    background: var(--bg-secondary);
}

.experience-grid-simple {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-6);
    max-width: 900px;
    margin: 0 auto;
}

.experience-card-simple {
    background: var(--bg-primary);
    padding: var(--spacing-6);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.experience-card-simple:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.experience-header-simple {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-4);
}

.experience-icon-simple {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-lg);
    flex-shrink: 0;
}

.experience-icon-simple.research {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
}

.experience-icon-simple.teaching {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.experience-info h3 {
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    margin: 0 0 var(--spacing-1) 0;
}

.experience-company {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--primary-color);
    margin: 0 0 var(--spacing-1) 0;
}

.experience-date {
    font-size: var(--font-size-sm);
    color: var(--text-light);
    margin: 0;
}

.experience-description-simple {
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

.experience-description-simple a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.experience-description-simple a:hover {
    text-decoration: underline;
}

/* Publications Section */
.publication-filters {
    display: flex;
    justify-content: center;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-8);
    flex-wrap: wrap;
}

.filter-btn {
    background: var(--bg-primary);
    color: var(--text-secondary);
    border: 2px solid var(--border-color);
    padding: var(--spacing-3) var(--spacing-6);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

.publications-grid {
    display: grid;
    gap: var(--spacing-8);
}

.publication-card {
    transition: all var(--transition-base);
}

.publication-card.hidden {
    display: none;
}

.publication-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-medium);
    overflow: hidden;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 0;
}

.publication-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.publication-image {
    padding: var(--spacing-6);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
}

.publication-image img {
    width: 100%;
    height: 120px;
    object-fit: cover;
    border-radius: var(--radius-base);
}

.publication-image video {
    width: 100%;
    max-width: 180px;
    height: auto;
    max-height: 120px;
    object-fit: cover;
    border-radius: var(--radius-base);
}

.publication-content {
    padding: var(--spacing-6);
}

.publication-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-2);
    line-height: 1.4;
}

.publication-venue {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: var(--spacing-3);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.publication-authors {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-4);
    line-height: 1.5;
}

.publication-authors a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.publication-authors a:hover {
    text-decoration: underline;
}

.publication-authors strong {
    color: var(--text-primary);
}

.publication-links {
    display: flex;
    gap: var(--spacing-3);
    flex-wrap: wrap;
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-1);
    padding: var(--spacing-2) var(--spacing-3);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius-base);
    font-size: var(--font-size-xs);
    font-weight: 500;
    transition: all var(--transition-base);
}

.pub-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
}

/* Contact Section */
.contact-section {
    background: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-6);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-4);
    padding: var(--spacing-6);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-lg);
    flex-shrink: 0;
}

.contact-details h3 {
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    margin-bottom: var(--spacing-2);
}

.contact-details p {
    color: var(--text-secondary);
    line-height: 1.5;
}

.contact-details a {
    color: var(--primary-color);
    text-decoration: none;
}

.contact-details a:hover {
    text-decoration: underline;
}

.contact-form-container {
    background: var(--bg-primary);
    padding: var(--spacing-8);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-medium);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-6);
}

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

.form-group input,
.form-group textarea {
    padding: var(--spacing-4);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-base);
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color var(--transition-base);
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Academic Services Section */
.services-section {
    background: var(--bg-secondary);
}

.services-badges {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-6);
    max-width: 800px;
    margin: 0 auto;
}

.service-badge {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-6);
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    transition: all var(--transition-base);
    text-align: left;
}

.service-badge:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
    border-color: var(--primary-color);
}

.badge-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-xl);
    flex-shrink: 0;
}

.badge-content h4 {
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    margin: 0 0 var(--spacing-1) 0;
    font-weight: 700;
}

.badge-content p {
    color: var(--text-secondary);
    margin: 0;
    font-size: var(--font-size-sm);
    font-weight: 500;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: var(--spacing-8) 0;
}

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

.footer-text p {
    color: var(--text-light);
}

.footer-links {
    display: flex;
    gap: var(--spacing-4);
}

.footer-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border-radius: var(--radius-full);
    text-decoration: none;
    transition: all var(--transition-base);
    font-size: var(--font-size-base);
}

.footer-link:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--spacing-12);
    }
    
    .hero-text {
        order: 2;
    }
    
    .hero-image {
        order: 1;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-12);
    }
    
    .publication-card {
        grid-template-columns: 1fr;
    }
    
    .publication-image {
        padding: var(--spacing-4);
    }
    
    .publication-image img {
        height: 200px;
    }
    
    /* Education responsive */
    .education-card {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-4);
    }
    
    .education-logo {
        width: 60px;
        height: 60px;
    }
    
    /* Experience responsive */
    .experience-grid-simple {
        grid-template-columns: 1fr;
        gap: var(--spacing-4);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-4);
    }
    
    .section {
        padding: var(--spacing-16) 0;
    }
    
    .nav-container {
        padding: 0 var(--spacing-4);
    }
    
    .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: var(--shadow-medium);
        border-top: 1px solid var(--border-color);
        padding: var(--spacing-6) 0;
    }
    
    .theme-toggle {
        width: 36px;
        height: 36px;
        padding: var(--spacing-1);
    }
    
    .theme-toggle i {
        font-size: var(--font-size-base);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-menu li {
        margin: var(--spacing-2) 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .name {
        font-size: var(--font-size-5xl);
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 200px;
        justify-content: center;
    }
    
    .profile-image {
        width: 250px;
        height: 250px;
    }
    
    .image-decoration {
        width: 250px;
        height: 250px;
    }
    
    .section-title {
        font-size: var(--font-size-3xl);
    }
    
    /* Education mobile */
    .education-card {
        padding: var(--spacing-6);
    }
    
    .education-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    /* Experience mobile */
    .experience-card-simple {
        padding: var(--spacing-4);
    }
    
    .experience-header-simple {
        gap: var(--spacing-3);
    }
    
    .experience-icon-simple {
        width: 40px;
        height: 40px;
        font-size: var(--font-size-base);
    }
    
    /* Services mobile */
    .services-badges {
        grid-template-columns: 1fr;
        gap: var(--spacing-4);
    }
    
    .service-badge {
        padding: var(--spacing-4);
        text-align: center;
        flex-direction: column;
        gap: var(--spacing-3);
    }
    
    .badge-icon {
        width: 48px;
        height: 48px;
        font-size: var(--font-size-lg);
    }
    
    .publication-card {
        grid-template-columns: 1fr;
    }
    
    .contact-form-container {
        padding: var(--spacing-6);
    }
    
    .footer-content {
        text-align: center;
    }
    
    .publication-filters {
        gap: var(--spacing-2);
    }
    
    .filter-btn {
        padding: var(--spacing-2) var(--spacing-4);
        font-size: var(--font-size-xs);
    }
}

@media (max-width: 480px) {
    .hero-content {
        gap: var(--spacing-8);
    }
    
    .name {
        font-size: var(--font-size-4xl);
    }
    
    .hero-subtitle {
        font-size: var(--font-size-xl);
    }
    
    .hero-description {
        font-size: var(--font-size-base);
    }
    
    .profile-image {
        width: 200px;
        height: 200px;
    }
    
    .image-decoration {
        width: 200px;
        height: 200px;
    }
    
    .interest-tags {
        justify-content: center;
    }
    
    .contact-email {
        font-size: var(--font-size-sm);
        padding: var(--spacing-2) var(--spacing-3);
    }
    
    .contact-email span {
        word-break: break-all;
    }

    /* Mobile adjustments for scroll indicator and back to top */
    .scroll-indicator {
        bottom: 20px;
    }
    
    .scroll-down span {
        display: none;
    }
    
    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
        font-size: var(--font-size-base);
    }
}

/* Dark Mode Toggle */
.theme-toggle {
    background: none;
    border: 1px solid transparent;
    border-radius: var(--radius-base);
    padding: var(--spacing-2);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.theme-toggle:hover {
    transform: scale(1.1);
}

.theme-toggle i {
    font-size: var(--font-size-lg);
    transition: transform var(--transition-base);
    color: inherit;
}

.theme-toggle:hover i {
    transform: rotate(180deg);
}

/* Hide/show icons based on theme */
/* Hide sun icon in light theme */
[data-theme="light"] .theme-toggle .fa-sun,
:root:not([data-theme="dark"]) .theme-toggle .fa-sun {
    display: none !important;
}

/* Hide moon icon in dark theme */
[data-theme="dark"] .theme-toggle .fa-moon {
    display: none !important;
}

/* Show moon icon in light theme */
[data-theme="light"] .theme-toggle .fa-moon,
:root:not([data-theme="dark"]) .theme-toggle .fa-moon {
    display: inline-block !important;
}

/* Show sun icon in dark theme */
[data-theme="dark"] .theme-toggle .fa-sun {
    display: inline-block !important;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .theme-toggle .fa-sun {
        display: inline-block !important;
    }
    :root:not([data-theme="light"]) .theme-toggle .fa-moon {
        display: none !important;
    }
}

/* Theme-specific colors for better visibility */
/* Light theme - show moon icon */
:root:not([data-theme="dark"]) .theme-toggle .fa-moon,
[data-theme="light"] .theme-toggle .fa-moon {
    color: #111827 !important;
    font-weight: 900 !important;
    font-size: 1.2rem !important;
}

/* Dark theme - show sun icon */
[data-theme="dark"] .theme-toggle .fa-sun,
:root:not([data-theme="light"]) .theme-toggle .fa-sun {
    color: #fbbf24 !important;
    font-weight: 600 !important;
    font-size: 1.2rem !important;
}

/* Fallback for all icons */
:root:not([data-theme="dark"]) .theme-toggle i {
    color: #111827 !important;
    font-weight: 900 !important;
}

[data-theme="light"] .theme-toggle i {
    color: #111827 !important;
    font-weight: 900 !important;
}

[data-theme="dark"] .theme-toggle i {
    color: #fbbf24 !important;
    font-weight: 600 !important;
}

/* Hover effects */
:root:not([data-theme="dark"]) .theme-toggle:hover {
    background: rgba(37, 99, 235, 0.1);
    border-radius: var(--radius-base);
}

:root:not([data-theme="dark"]) .theme-toggle:hover i {
    color: #2563eb !important;
}

[data-theme="light"] .theme-toggle:hover {
    background: rgba(37, 99, 235, 0.1);
    border-radius: var(--radius-base);
}

[data-theme="light"] .theme-toggle:hover i {
    color: #2563eb !important;
}

[data-theme="dark"] .theme-toggle:hover {
    background: rgba(251, 191, 36, 0.2);
    border-radius: var(--radius-base);
}

[data-theme="dark"] .theme-toggle:hover i {
    color: #fcd34d !important;
}

/* Dark theme support for scroll indicator */
[data-theme="dark"] .scroll-down {
    color: var(--text-secondary);
}

[data-theme="dark"] .scroll-down:hover {
    color: var(--primary-color);
}

/* Dark theme support for back to top button */
[data-theme="dark"] .back-to-top {
    color: var(--text-secondary);
    border-color: var(--text-secondary);
}

[data-theme="dark"] .back-to-top:hover {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* Selection */
::selection {
    background: var(--primary-color);
    color: white;
}

/* Scroll down indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
}

.scroll-down {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: all var(--transition-base);
    animation: bounce 2s infinite;
}

.scroll-down:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

.scroll-down i {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-1);
}

.scroll-down span {
    font-size: var(--font-size-xs);
    opacity: 0.8;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

/* Back to top button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: transparent;
    color: var(--text-secondary);
    border: 2px solid var(--text-secondary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
    cursor: pointer;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-medium);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    color: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-large);
}