/* CSS Variables for theming */
:root {
    --primary-color: #4ECDC4;
    --secondary-color: #FF6B6B;
    --accent-color: #45B7D1;
    --success-color: #96CEB4;
    --warning-color: #FECA57;
    
    --bg-primary: #0D1117;
    --bg-secondary: #161B22;
    --bg-tertiary: #21262D;
    --text-primary: #F0F6FC;
    --text-secondary: #8B949E;
    --text-muted: #656D76;
    
    --gradient-primary: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    --gradient-secondary: linear-gradient(135deg, var(--secondary-color), var(--warning-color));
    
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    --font-primary: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

/* Light theme */
[data-theme="light"] {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F6F8FA;
    --bg-tertiary: #EAEEF2;
    --text-primary: #24292F;
    --text-secondary: #656D76;
    --text-muted: #8B949E;
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: var(--transition);
}

/* Custom cursor */
.cursor {
    position: fixed;
    width: 8px;
    height: 8px;
    background: var(--primary-color);
    border-radius: 50%;
    pointer-events: none;
    z-index: 9999;
    transition: transform 0.1s ease;
}

.cursor-follower {
    position: fixed;
    width: 30px;
    height: 30px;
    border: 2px solid var(--primary-color);
    border-radius: 50%;
    pointer-events: none;
    z-index: 9998;
    transition: transform 0.3s ease;
    opacity: 0.5;
}

/* Preloader */
#preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    transition: opacity 0.5s ease;
}

.loader {
    text-align: center;
}

.neural-network {
    position: relative;
    width: 100px;
    height: 100px;
    margin: 0 auto 20px;
}

.node {
    position: absolute;
    width: 12px;
    height: 12px;
    background: var(--primary-color);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

.node:nth-child(1) { top: 20px; left: 20px; animation-delay: 0s; }
.node:nth-child(2) { top: 20px; right: 20px; animation-delay: 0.5s; }
.node:nth-child(3) { bottom: 20px; left: 20px; animation-delay: 1s; }
.node:nth-child(4) { bottom: 20px; right: 20px; animation-delay: 1.5s; }

.connection {
    position: absolute;
    background: var(--accent-color);
    height: 2px;
    animation: glow 2s infinite;
}

.connection:nth-child(5) {
    top: 26px;
    left: 32px;
    width: 36px;
    transform: rotate(0deg);
}

.connection:nth-child(6) {
    top: 45px;
    left: 26px;
    width: 30px;
    transform: rotate(90deg);
}

.connection:nth-child(7) {
    bottom: 45px;
    right: 26px;
    width: 30px;
    transform: rotate(90deg);
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.2); opacity: 0.7; }
}

@keyframes glow {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; box-shadow: 0 0 10px var(--accent-color); }
}

/* Particles background */
#particles-js {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(13, 17, 23, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(48, 54, 61, 0.5);
    z-index: 1000;
    transition: var(--transition);
}

.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;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-text {
    color: var(--text-primary);
}

.logo-ai {
    color: var(--primary-color);
    font-family: var(--font-mono);
}

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

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

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

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

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

.nav-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--text-secondary);
    color: var(--text-secondary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
}

.theme-toggle:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: var(--transition);
}

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

/* Sections */
.section {
    padding: 100px 0;
    position: relative;
}

.bg-secondary {
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 20px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    width: 100%;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-family: var(--font-mono);
    margin-bottom: 20px;
    min-height: 60px;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 40px;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: var(--font-mono);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 5px;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

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

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

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

.btn-linkedin {
    background: #0077B5;
    color: white;
}

.btn-linkedin:hover {
    background: #005885;
    transform: translateY(-2px);
}

/* Hero Visual */
.hero-visual {
    position: relative;
    height: 500px;
}

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

.floating-card {
    position: absolute;
    background: var(--bg-tertiary);
    padding: 1rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(78, 205, 196, 0.3);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: var(--shadow-md);
    animation: float 6s ease-in-out infinite;
}

.floating-card i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.ai-card {
    top: 10%;
    right: 20%;
    animation-delay: 0s;
}

.auto-card {
    top: 50%;
    left: 10%;
    animation-delay: 2s;
}

.ml-card {
    bottom: 20%;
    right: 30%;
    animation-delay: 4s;
}

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

.hero-3d-container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 300px;
    height: 300px;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    animation: bounce 2s infinite;
}

.scroll-line {
    width: 2px;
    height: 30px;
    background: var(--primary-color);
    position: relative;
}

.scroll-line::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 10px solid var(--primary-color);
}

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

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

.about-intro h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

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

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

.credential {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    border: 1px solid rgba(78, 205, 196, 0.2);
}

.credential i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.credential h4 {
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.credential p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.skills-container h3 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.skill-category {
    margin-bottom: 2rem;
}

.skill-category h4 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.skill-category i {
    color: var(--accent-color);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 0.5rem;
}

.skill-item {
    background: var(--bg-tertiary);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    border: 1px solid rgba(78, 205, 196, 0.2);
    transition: var(--transition);
}

.skill-item:hover {
    background: rgba(78, 205, 196, 0.1);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

/* Research Section */
.research-content {
    max-width: 800px;
    margin: 0 auto;
}

.research-card {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 2rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
    box-shadow: var(--shadow-lg);
}

.research-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.research-logo img {
    width: 60px;
    height: 60px;
    object-fit: contain;
    background: white;
    border-radius: 8px;
    padding: 8px;
}

.research-info h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

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

.research-description {
    margin-bottom: 2rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.research-objectives h4 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.research-objectives ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.research-objectives li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.research-objectives i {
    color: var(--accent-color);
}

.research-impact h4 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.impact-metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.metric {
    text-align: center;
    padding: 1rem;
    background: rgba(78, 205, 196, 0.1);
    border-radius: var(--border-radius);
    border: 1px solid rgba(78, 205, 196, 0.3);
}

.metric-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: var(--font-mono);
}

.metric-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Experience Timeline */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
    transform: translateX(-50%);
}

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

.timeline-marker {
    position: absolute;
    left: 50%;
    top: 2rem;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 1;
    box-shadow: 0 0 0 4px var(--bg-primary);
}

.timeline-content {
    width: 45%;
    position: relative;
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-left: 55%;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-right: 55%;
}

.experience-card {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 2rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}
.experience-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.experience-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.company-logo {
    width: 50px;
    height: 50px;
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: white;
}

.company-logo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.company-initial {
    width: 50px;
    height: 50px;
    border-radius: 8px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1.5rem;
}

.experience-info h3 {
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.experience-info h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.location, .duration {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.location i, .duration i {
    color: var(--accent-color);
}

.experience-description ul {
    list-style: none;
    margin-bottom: 1.5rem;
}

.experience-description li {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    padding-left: 1rem;
    position: relative;
    line-height: 1.6;
}

.experience-description li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.experience-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    background: rgba(78, 205, 196, 0.1);
    color: var(--primary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.8rem;
    border: 1px solid rgba(78, 205, 196, 0.3);
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid rgba(78, 205, 196, 0.2);
    transition: var(--transition);
    position: relative;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.project-image {
    height: 200px;
    background: var(--gradient-primary);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-icon {
    font-size: 4rem;
    color: rgba(255, 255, 255, 0.3);
    z-index: 1;
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

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

.project-link {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    font-size: 1.2rem;
    transition: var(--transition);
}

.project-link:hover {
    background: var(--accent-color);
    transform: scale(1.1);
}

.project-category {
    position: absolute;
    top: 1rem;
    left: 1rem;
    background: rgba(0, 0, 0, 0.8);
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    z-index: 2;
}

.project-content {
    padding: 2rem;
}

.project-content h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.project-content p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.project-metrics {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid rgba(78, 205, 196, 0.2);
}

/* Publications Section */
.publications-content {
    max-width: 800px;
    margin: 0 auto;
}

.publication-item {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 2rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
    margin-bottom: 2rem;
}

.publication-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.4rem;
}

.publication-author {
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 1rem;
}

.publication-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.publication-metrics {
    display: flex;
    gap: 2rem;
    margin-bottom: 1.5rem;
}

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

.accomplishments {
    margin-top: 3rem;
}

.accomplishments h3 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    font-size: 2rem;
}

.accomplishment-item {
    display: flex;
    gap: 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
    margin-bottom: 1.5rem;
}

.accomplishment-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.accomplishment-content h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.accomplishment-org {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

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

/* Education & Certifications */
.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.education-card {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 2rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
}

.education-header {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.education-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.education-info h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.education-institution {
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.education-period, .education-grade {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.education-subjects {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.subject-tag {
    background: rgba(78, 205, 196, 0.1);
    color: var(--primary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.8rem;
    border: 1px solid rgba(78, 205, 196, 0.3);
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.certification-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
    transition: var(--transition);
}

.certification-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.cert-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-secondary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.cert-info h4 {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.cert-info p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.cert-link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.cert-link:hover {
    text-decoration: underline;
}

/* Languages Section */
.languages-section {
    margin-top: 3rem;
}

.languages-title {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

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

.language-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border: 1px solid rgba(78, 205, 196, 0.2);
    transition: var(--transition);
}

.language-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.language-name {
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.1rem;
}

.language-level {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.contact-details h4 {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.contact-details p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

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

.contact-link:hover {
    text-decoration: underline;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.social-link {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    font-size: 1.2rem;
    transition: var(--transition);
}

.social-link.linkedin {
    background: #0077B5;
}

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

.social-link.email {
    background: #D14836;
}

.social-link:hover {
    transform: translateY(-3px) scale(1.1);
}

/* Contact Form */
.contact-form {
    background: var(--bg-tertiary);
    padding: 2rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(78, 205, 196, 0.2);
}

.form-group {
    position: relative;
    margin-bottom: 2rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    background: var(--bg-primary);
    border: 2px solid var(--text-secondary);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
    resize: vertical;
}

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

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

.form-group label {
    position: absolute;
    top: 1rem;
    left: 1rem;
    color: var(--text-secondary);
    font-size: 1rem;
    transition: var(--transition);
    pointer-events: none;
}

.form-group input:focus + label,
.form-group input:not(:placeholder-shown) + label,
.form-group textarea:focus + label,
.form-group textarea:not(:placeholder-shown) + label {
    top: -0.5rem;
    left: 0.5rem;
    font-size: 0.8rem;
    color: var(--primary-color);
    background: var(--bg-tertiary);
    padding: 0 0.5rem;
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    padding: 3rem 0 2rem;
    border-top: 1px solid rgba(78, 205, 196, 0.2);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 3fr;
    gap: 3rem;
    align-items: start;
    margin-bottom: 2rem;
}

.footer-info h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.footer-info p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.footer-section h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

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

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

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--primary-color);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .hero-visual {
        height: 300px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .timeline::before {
        left: 20px;
    }
    
    .timeline-marker {
        left: 20px;
        transform: translateX(-50%);
    }
    
    .timeline-content {
        width: calc(100% - 60px);
        margin-left: 60px !important;
        margin-right: 0 !important;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-primary);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: var(--transition);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .section-title {
        font-size: 2.5rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .education-grid {
        grid-template-columns: 1fr;
    }
    
    .certifications-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    
    .experience-card,
    .project-card,
    .research-card {
        padding: 1.5rem;
    }
    
    .impact-metrics {
        grid-template-columns: 1fr;
    }
}

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

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

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-color);
}

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

/* Focus outline */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}