:root {
    /* Colors */
    --bg-main: #0b0f19;
    --bg-secondary: #111827;
    --bg-card: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-blue: #3b82f6;
    --accent-purple: #a855f7;
    --gradient-primary: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    
    /* Typography */
    --font-main: 'Inter', sans-serif;
    
    /* Spacing & Layout */
    --max-width: 1100px;
    --section-padding: 100px 20px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.4s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

/* Typography Utility */
.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
}

.section-container {
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60%;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 1.8rem;
    border-radius: 6px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    border: none;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -10px var(--accent-blue);
}

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

.btn-outline:hover {
    background: rgba(59, 130, 246, 0.1);
    transform: translateY(-2px);
}

/* Navigation */
#navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(11, 15, 25, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all var(--transition-fast);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1.5rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

.logo span {
    color: var(--accent-blue);
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-blue);
}

.nav-cta {
    border: 1px solid var(--accent-blue);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    color: var(--accent-blue) !important;
}

.nav-cta:hover {
    background: rgba(59, 130, 246, 0.1);
}

.hamburger {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 0 20px;
    max-width: var(--max-width);
    margin: 0 auto;
}

.hero-content {
    max-width: 800px;
}

.greeting {
    color: var(--accent-blue);
    font-weight: 500;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.name {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1rem;
    color: #ffffff;
}

.role {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.divider {
    color: var(--text-secondary);
    font-weight: 300;
}

.tagline {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 600px;
    line-height: 1.8;
}

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

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

.about-text p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    max-width: 800px;
}

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

/* Experience Section & Timeline */
.experience-section {
    padding: var(--section-padding);
    background-color: var(--bg-primary);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 2rem auto 0 auto;
    padding-left: 2rem;
    border-left: 2px solid rgba(59, 130, 246, 0.3);
}

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: -2.55rem;
    top: 0.25rem;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-blue);
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 12px rgba(59, 130, 246, 0.8);
}

.timeline-content {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform var(--transition-medium), border-color var(--transition-medium);
}

.timeline-content:hover {
    transform: translateY(-4px);
    border-color: rgba(59, 130, 246, 0.3);
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.4);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.2rem;
}

.role-title {
    font-size: 1.25rem;
    color: var(--text-primary);
    font-weight: 700;
}

.company-name {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-top: 0.25rem;
}

.experience-date {
    font-size: 0.85rem;
    color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    padding: 0.35rem 0.85rem;
    border-radius: 20px;
    font-weight: 600;
}

.experience-bullets {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.experience-bullets li {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.bullet-icon {
    color: var(--accent-blue);
    margin-top: 0.3rem;
    font-size: 0.8rem;
    flex-shrink: 0;
}

/* Achievements Section */
.achievements-section {
    padding: var(--section-padding);
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.achievement-card {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform var(--transition-fast);
}

.achievement-card:hover {
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.3);
}

.icon-container {
    width: 50px;
    height: 50px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--accent-blue);
    margin-bottom: 1.5rem;
}

.achievement-card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
}

.achievement-card p {
    color: var(--text-secondary);
}

.github-badge-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(30, 41, 59, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.github-badge-tag:hover {
    border-color: var(--accent-blue);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.2);
}

/* Projects Section */
.projects-section {
    padding: var(--section-padding);
    background-color: var(--bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
}

.project-card {
    background: var(--bg-card);
    border-radius: 12px;
    overflow: hidden;
    transition: transform var(--transition-medium);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px -15px rgba(0,0,0,0.5);
}

.project-image {
    position: relative;
    width: 100%;
    height: 220px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-medium);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.dynamic-repo-image {
    background: linear-gradient(135deg, #1e293b, #0b0f19);
    display: flex;
    align-items: center;
    justify-content: center;
}

.repo-visual-fallback {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    color: var(--text-secondary);
    transition: transform var(--transition-medium);
}

.project-card:hover .repo-visual-fallback {
    transform: scale(1.1);
    color: var(--accent-blue);
}

.repo-visual-fallback i {
    font-size: 4rem;
    opacity: 0.8;
}

.repo-lang-label {
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    background: rgba(255, 255, 255, 0.05);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.project-links-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(11, 15, 25, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

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

.icon-link {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background: var(--bg-main);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: var(--text-primary);
    transition: background var(--transition-fast);
}

.icon-link:hover {
    background: var(--accent-blue);
}

.project-info {
    padding: 2rem;
}

.project-title {
    font-size: 1.4rem;
    margin-bottom: 1rem;
}

.project-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.tech-stack span {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.1);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
}

/* Research Section */
.research-section {
    padding: var(--section-padding);
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 700px;
}

.publication-container {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.publication-card {
    display: flex;
    background: rgba(30, 41, 59, 0.4);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    overflow: hidden;
    transition: all var(--transition-medium);
    position: relative;
}

.publication-card:hover {
    transform: translateY(-10px);
    border-color: rgba(59, 130, 246, 0.4);
    box-shadow: 0 20px 50px -15px rgba(59, 130, 246, 0.2);
}

.publication-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    width: 100%;
    background: radial-gradient(circle at top right, rgba(168, 85, 247, 0.1), transparent);
    pointer-events: none;
}

.publication-image {
    flex: 1;
    min-width: 350px;
    position: relative;
    overflow: hidden;
}

.publication-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-medium);
}

.publication-card:hover .publication-image img {
    transform: scale(1.05);
}

.publication-content {
    flex: 1.5;
    padding: 3rem;
    display: flex;
    flex-direction: column;
}

.publication-badge {
    display: inline-block;
    width: fit-content;
    padding: 0.4rem 1rem;
    background: rgba(59, 130, 246, 0.1);
    color: var(--accent-blue);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 1.2rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.1);
    animation: badgePulse 3s infinite;
}

@keyframes badgePulse {
    0% { box-shadow: 0 0 5px rgba(59, 130, 246, 0.2); }
    50% { box-shadow: 0 0 20px rgba(59, 130, 246, 0.4); }
    100% { box-shadow: 0 0 5px rgba(59, 130, 246, 0.2); }
}

.publication-title {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #fff;
}

.elite-tag {
    font-size: 0.85rem;
    color: var(--accent-purple);
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.publication-meta {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.publication-meta span {
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.publication-meta span i {
    color: var(--accent-blue);
}

.publication-description {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.publication-highlights {
    list-style: none;
    margin-bottom: 2rem;
}

.publication-highlights li {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.8rem;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.publication-highlights li i {
    color: var(--accent-blue);
    margin-top: 4px;
}

.publication-actions {
    display: flex;
    gap: 1rem;
    margin-top: auto;
}

@media (max-width: 992px) {
    .publication-card {
        flex-direction: column;
    }
    
    .publication-image {
        height: 250px;
        min-width: 100%;
    }
    
    .publication-content {
        padding: 2rem;
    }
}

@media (max-width: 600px) {
    .publication-actions {
        flex-direction: column;
    }
    
    .publication-meta {
        flex-wrap: wrap;
        gap: 1rem;
    }
}

/* Skills Section */
.skills-section {
    padding: var(--section-padding);
}

.skills-wrapper {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
}

.skill-category h3 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    border-left: 3px solid var(--accent-purple);
    padding-left: 10px;
}

.skill-tags {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.skill-tags span {
    color: var(--text-secondary);
    font-weight: 500;
    display: flex;
    align-items: center;
}

.skill-tags span::before {
    content: '▹';
    color: var(--accent-blue);
    margin-right: 10px;
    font-size: 1.2rem;
}

/* Resume Section */
.resume-section {
    padding: var(--section-padding);
    background-color: var(--bg-secondary);
    text-align: center;
}

.resume-box {
    max-width: 600px;
    margin: 0 auto;
    padding: 4rem 2rem;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.resume-box h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.resume-box p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
}

.btn-large i {
    margin-right: 8px;
}

/* Contact Section */
.contact-section {
    padding: 80px 20px 20px;
    text-align: center;
}

.contact-text {
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 3rem;
    font-size: 1.1rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin-bottom: 5rem;
}

.contact-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: 12px;
    width: 160px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.contact-card:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
    transform: translateY(-5px);
}

.contact-card i {
    font-size: 2rem;
}

.contact-card span {
    font-weight: 500;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Reveal Animations */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--bg-main);
        flex-direction: column;
        padding: 2rem 0;
        text-align: center;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .hamburger {
        display: block;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .role {
        font-size: 1.8rem;
    }
    
    .divider {
        display: none;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        text-align: center;
    }
}

/* Typing Effect */
.cursor {
    display: inline-block;
    width: 3px;
    background-color: var(--accent-blue);
    margin-left: 2px;
    animation: blink 1s infinite;
}
.cursor.typing {
    animation: none;
}
@keyframes blink {
    0% { background-color: var(--accent-blue); }
    49% { background-color: var(--accent-blue); }
    50% { background-color: transparent; }
    99% { background-color: transparent; }
    100% { background-color: var(--accent-blue); }
}

/* Project Filters */
.project-filters {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem;
}
.filter-btn {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid rgba(255,255,255,0.1);
    padding: 0.5rem 1.5rem;
    border-radius: 30px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}
.filter-btn:hover, .filter-btn.active {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.project-card.hide {
    display: none;
}

/* Skill Icons */
.skill-icon {
    width: 20px;
    text-align: center;
    margin-right: 8px;
    color: var(--accent-purple);
}
.skill-tags span::before {
    display: none; /* Remove previous arrow */
}

/* Contact Form Styling */
.contact-form-container {
    max-width: 600px;
    margin: 3rem auto 0;
    padding: 2.5rem;
    background: rgba(30, 41, 59, 0.4);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    text-align: left;
}

.contact-form-container:hover {
    border-color: rgba(59, 130, 246, 0.2);
}

.form-row {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-group {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.form-row .form-group {
    margin-bottom: 0;
}

.form-group label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-blue);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem 1.2rem;
    background: rgba(11, 15, 25, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.95rem;
    outline: none;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent-purple);
    background: rgba(11, 15, 25, 0.8);
    box-shadow: 0 0 10px rgba(168, 85, 247, 0.2);
}

.form-submit-btn {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 0.9rem 1.8rem;
    border-radius: 8px;
    font-size: 1.05rem;
}

@media (max-width: 600px) {
    .form-row {
        flex-direction: column;
        gap: 1.5rem;
    }
}