:root {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --secondary-color: #64748b;
    --accent-color: #06b6d4;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-light: #ffffff;
    
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-light: #94a3b8;
    
    --border-color: #334155;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6), 0 10px 10px -5px rgba(0, 0, 0, 0.5);
    
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    
    --border-radius-sm: 0.375rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
}

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

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

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

body.menu-open {
    overflow: hidden;
}

.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease;
}

.loader {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all var(--transition-base);
    border-bottom: 1px solid transparent;
}

.navbar.scrolled {
    box-shadow: var(--shadow-lg);
    border-bottom-color: var(--border-color);
    background: rgba(15, 23, 42, 0.98);
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 0.375rem;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
    border-radius: 2px;
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
    position: relative;
    padding: 0.5rem 0;
}

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

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

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

.lang-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    font-size: 1.25rem;
    transition: all var(--transition-fast);
}

.lang-toggle:hover {
    background: var(--bg-tertiary);
    transform: scale(1.05);
}

.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    position: relative;
    padding: 8rem 2rem 4rem;
}

.hero-container {
    max-width: 800px;
    width: 100%;
    text-align: center;
}

.hero-content {
    opacity: 0;
    transform: translateY(30px);
    transition: all var(--transition-slow);
}

.hero-content.animate-in {
    opacity: 1;
    transform: translateY(0);
}

.hero-image-wrapper {
    margin-bottom: 2rem;
}

.hero-image-placeholder {
    width: 160px;
    height: 160px;
    margin: 0 auto;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: var(--shadow-lg);
}

.hero-image-placeholder svg {
    width: 80px;
    height: 80px;
}

.hero-image {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: 0 0 0 4px var(--bg-secondary), var(--shadow-xl);
    border: 3px solid var(--primary-color);
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-weight: 500;
}

.hero-badges {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2.5rem;
}

.badge {
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-lg);
    font-size: 0.875rem;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: var(--border-radius-md);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
}

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

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

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

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

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-light);
    font-size: 0.875rem;
    animation: bounce 2s infinite;
}

.scroll-indicator svg {
    width: 24px;
    height: 24px;
}

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

.section {
    padding: 5rem 2rem;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    margin: 1rem auto 0;
    border-radius: 2px;
}

.about-section {
    background: var(--bg-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
}

.about-text .lead {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.info-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.info-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.info-item svg {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
    flex-shrink: 0;
}

.info-item strong {
    display: block;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    font-weight: 600;
}

.info-item p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.skills-section h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.skills-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.skill-category {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.skill-category:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.skill-category h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.skill-list {
    list-style: none;
}

.skill-list li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    font-size: 0.9375rem;
    position: relative;
    padding-left: 1.5rem;
}

.skill-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

.timeline {
    position: relative;
    padding: 2rem 0;
}

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

.timeline-item {
    display: flex;
    margin-bottom: 3rem;
    position: relative;
    opacity: 0;
    transition: all var(--transition-slow);
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
    transform: translateX(-50px);
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
    transform: translateX(50px);
}

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

.timeline-content {
    flex: 1;
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    margin: 0 2rem;
    max-width: calc(50% - 3rem);
    border: 1px solid var(--border-color);
}

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

.timeline-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.timeline-header .company {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 1rem;
}

.timeline-period {
    background: var(--bg-secondary);
    padding: 0.375rem 0.75rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
    white-space: nowrap;
}

.timeline-location {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

.timeline-responsibilities {
    list-style: none;
}

.timeline-responsibilities li {
    padding: 0.375rem 0;
    color: var(--text-secondary);
    font-size: 0.9375rem;
    position: relative;
    padding-left: 1.25rem;
}

.timeline-responsibilities li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

.certifications {
    margin-top: 4rem;
}

.certifications h3 {
    font-size: 1.75rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
}

.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.cert-card {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.cert-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-8px);
}

.cert-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.cert-icon svg {
    width: 32px;
    height: 32px;
}

.cert-card h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.cert-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

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

.projects-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    color: var(--text-secondary);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.9375rem;
}

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

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-xl);
    padding: 2rem;
    transition: all var(--transition-base);
    opacity: 1;
    transform: translateY(0);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    padding: 0.625rem 1.25rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    transition: all var(--transition-base);
}

.project-link:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.project-link svg {
    width: 16px;
    height: 16px;
}

.project-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-8px);
    border-color: var(--primary-color);
}

.project-card.project-placeholder {
    border-style: dashed;
    opacity: 0.7;
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.project-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
}

.project-icon svg {
    width: 24px;
    height: 24px;
}

.project-status {
    padding: 0.375rem 0.75rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    background: var(--success-color);
    color: white;
}

.project-status.status-active {
    background: var(--accent-color);
}

.project-status.status-progress {
    background: var(--warning-color);
}

.project-status.status-future {
    background: var(--secondary-color);
}

.project-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.project-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

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

.tech-tag {
    padding: 0.375rem 0.75rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.achievement-highlight {
    margin-top: 4rem;
    padding: 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--border-radius-xl);
    display: flex;
    align-items: center;
    gap: 2rem;
    color: white;
    box-shadow: var(--shadow-xl);
}

.achievement-icon {
    font-size: 4rem;
    flex-shrink: 0;
}

.achievement-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.achievement-content p {
    font-size: 1rem;
    opacity: 0.95;
    line-height: 1.6;
}

.contact-section {
    background: var(--bg-primary);
}

.contact-content {
    max-width: 900px;
    margin: 0 auto;
}

.contact-intro {
    text-align: center;
    margin-bottom: 3rem;
}

.contact-intro .lead {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.contact-method {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    text-decoration: none;
    color: inherit;
    border: 1px solid var(--border-color);
}

.contact-method:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    flex-shrink: 0;
}

.contact-icon svg {
    width: 24px;
    height: 24px;
}

.contact-method strong {
    display: block;
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.contact-method p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.additional-info {
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.additional-info h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.additional-info ul {
    list-style: none;
}

.additional-info li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.additional-info li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

.footer {
    background: #000000;
    color: var(--text-light);
    padding: 2rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer-content p {
    margin: 0.5rem 0;
    font-size: 0.9375rem;
}

.footer-tech {
    opacity: 0.7;
}

.scroll-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

.scroll-top svg {
    width: 24px;
    height: 24px;
}