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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #7c3aed;
    --dark: #1f2937;
    --light: #f9fafb;
    --gray: #6b7280;
    --light-gray: #e5e7eb;
    --success: #10b981;
    --warning: #f59e0b;
    
    --font-main: 'Inter', sans-serif;
    --font-mono: 'Roboto Mono', monospace;
    
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 8px;
}

body {
    font-family: var(--font-main);
    line-height: 1.6;
    color: var(--dark);
    background: white;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: 5rem 0;
}

.bg-light {
    background-color: var(--light);
}

.bg-dark {
    background-color: var(--dark);
    color: white;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-align: center;
}

.section-title.light {
    color: white;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray);
    text-align: center;
    margin-bottom: 3rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.light .section-subtitle {
    color: #d1d5db;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark);
    text-decoration: none;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    transition: color 0.3s;
}

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

.btn-cv {
    background: var(--primary);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--dark);
}

/* Hero Section */
.hero {
    padding-top: 8rem;
    padding-bottom: 5rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.highlight {
    color: var(--primary);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray);
    margin-bottom: 2rem;
}

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

.metric {
    text-align: center;
}

.metric-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.metric-label {
    font-size: 0.875rem;
    color: var(--gray);
}

.hero-cta {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.btn-primary, .btn-secondary {
    padding: 0.75rem 2rem;
    border-radius: var(--radius);
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
}

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

.btn-secondary:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
}

.hero-image {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
}

.code-snippet {
    font-family: var(--font-mono);
    background: #1e293b;
    color: #e2e8f0;
    padding: 1.5rem;
    border-radius: calc(var(--radius) - 2px);
    overflow-x: auto;
}

.code-snippet code {
    font-size: 0.875rem;
    line-height: 1.5;
}

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
}

.expertise-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.expertise-category h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

.expertise-category ul {
    list-style: none;
}

.expertise-category li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--light-gray);
}

.expertise-category li:last-child {
    border-bottom: none;
}

.about-quick-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary);
}

.info-card h4 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.info-card p {
    color: var(--gray);
    margin-bottom: 0.25rem;
}

.info-card em {
    color: var(--primary);
    font-size: 0.875rem;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.project-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    border-top: 4px solid transparent;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

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

.tag {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.tag-nlp { background: #dbeafe; color: #1e40af; }
.tag-rag { background: #f0f9ff; color: #0369a1; }
.tag-genai { background: #f0fdf4; color: #166534; }
.tag-ml { background: #fef3c7; color: #92400e; }
.tag-llm { background: #fce7f3; color: #9d174d; }
.tag-innovation { background: #f3e8ff; color: #7e22ce; }
.tag-dl { background: #dcfce7; color: #15803d; }
.tag-production { background: #fef9c3; color: #854d0e; }

.project-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--dark);
}

.project-description {
    color: var(--gray);
    margin-bottom: 1.5rem;
    min-height: 80px;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.project-tech span {
    background: var(--light);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
    color: var(--gray);
}

.project-results {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.result {
    text-align: center;
    flex: 1;
}

.result-number {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.result-label {
    font-size: 0.75rem;
    color: var(--gray);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-link {
    display: inline-block;
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s;
}

.project-link:hover {
    gap: 0.5rem;
}

.project-link:hover::after {
    margin-left: 0.5rem;
}

/* Publications Preview */
.publications-preview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.publication-highlight {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary);
}

.publication-highlight h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--dark);
}

.pub-title {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.pub-meta {
    color: var(--gray);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

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

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

/* Contact Section */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
}

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

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

.contact-item i {
    font-size: 1.5rem;
    color: var(--primary);
    margin-top: 0.25rem;
}

.contact-item h4 {
    margin-bottom: 0.25rem;
    color: white;
}

.contact-item a, .contact-item p {
    color: #d1d5db;
    text-decoration: none;
}

.contact-item a:hover {
    color: white;
    text-decoration: underline;
}

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

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    text-decoration: none;
    transition: all 0.3s;
}

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

.contact-form {
    background: rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: var(--radius);
    backdrop-filter: blur(10px);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius);
    font-family: var(--font-main);
    font-size: 1rem;
    color: var(--dark);
    transition: border-color 0.3s;
}

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

/* Footer */
.footer {
    background: #111827;
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer p {
    margin-bottom: 0.5rem;
    color: #9ca3af;
}

.footer-status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.status-indicator {
    width: 8px;
    height: 8px;
    background: var(--success);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Responsive Design */
@media (max-width: 992px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .contact-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-metrics {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .hero-cta {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .expertise-grid {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: 3rem 0;
    }
}