:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f6f8fa;
    --bg-tertiary: #eaeef2;
    --border-primary: #d0d7de;
    --border-secondary: #dde1e6;
    --text-primary: #1f2328;
    --text-secondary: #59636e;
    --text-tertiary: #6e7781;
    --accent: #0969da;
    --accent-soft: rgba(9,105,218,0.08);
    --accent-muted: #0a4b8a;
    --success: #1a7f37;
    --shadow-md: 0 4px 12px rgba(0,0,0,0.02);
    --radius-md: 8px;
    --radius-lg: 12px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.75rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 4rem;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    font-weight: 400;
    transition: background-color 0.15s, color 0.15s, border-color 0.15s;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

h1, h2, h3, h4 {
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text-primary);
}

h1 {
    font-size: 3.2rem;
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-primary);
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

a {
    text-decoration: none;
    color: var(--accent);
    font-weight: 500;
    transition: color 0.1s;
}

a:hover {
    color: var(--accent-muted);
    text-decoration: underline;
}

.mono, .badge, .tech-tag, .cert-badge, .stat-label, .card-tag {
    font-family: 'JetBrains Mono', 'SF Mono', monospace;
    font-size: 0.75rem;
    letter-spacing: -0.01em;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-primary);
    margin-bottom: var(--spacing-lg);
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

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

.nav-links a:hover {
    color: var(--text-primary);
    text-decoration: none;
}

.nav-links a.active {
    color: var(--accent);
    font-weight: 600;
}

.theme-toggle {
    background: transparent;
    border: 1px solid var(--border-primary);
    border-radius: 30px;
    padding: 0.4rem 1rem;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    font-family: 'JetBrains Mono', monospace;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    transition: all 0.1s;
}

.theme-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-soft);
}

.hero {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-primary);
}

.hero-main {
    max-width: 70%;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-tertiary);
    margin-top: 0.5rem;
    font-weight: 400;
    max-width: 600px;
}

.badge-container {
    display: flex;
    gap: 0.5rem;
    margin-top: var(--spacing-sm);
    flex-wrap: wrap;
}

.badge {
    background-color: var(--accent-soft);
    color: var(--accent);
    padding: 0.2rem 0.9rem;
    border-radius: 30px;
    font-size: 0.7rem;
    font-weight: 500;
    border: 1px solid rgba(9,105,218,0.2);
    text-transform: uppercase;
}

.stat-grid {
    display: flex;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1;
}

.stat-label {
    font-size: 0.7rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    margin-top: 4px;
}

.code-snippet {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    padding: 0.6rem 1rem;
    border-radius: var(--radius-md);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
}

.timeline {
    margin: var(--spacing-lg) 0 var(--spacing-xl);
}

.timeline-item {
    display: flex;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-primary);
}

.timeline-left {
    min-width: 120px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--text-tertiary);
    font-weight: 500;
}

.timeline-right {
    flex: 1;
}

.timeline-title {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 0.2rem;
    color: var(--text-primary);
}

.timeline-sub {
    color: var(--text-tertiary);
    font-size: 0.85rem;
    margin-bottom: 0.4rem;
    font-family: 'JetBrains Mono', monospace;
}

.timeline-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 0.8rem;
    margin-bottom: var(--spacing-xl);
}

.skill-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    padding: 0.8rem 1rem;
    display: flex;
    align-items: center;
    gap: 0.7rem;
}

.skill-card i {
    font-size: 1.4rem;
    color: var(--accent);
    width: 24px;
    text-align: center;
}

.skill-card span {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.certs-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.7rem;
    margin: var(--spacing-sm) 0 var(--spacing-xl);
}

.cert-badge {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    padding: 0.4rem 1.2rem;
    border-radius: 40px;
    font-size: 0.7rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: border-color 0.15s, color 0.15s;
    cursor: default;
    pointer-events: none;
}

.cert-badge i {
    color: var(--accent);
    font-size: 0.8rem;
}

.cert-badge:hover {
    border-color: var(--accent);
    color: var(--text-primary);
    background: var(--bg-tertiary);
    text-decoration: none;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    border: 1px solid var(--border-primary);
    transition: border-color 0.15s, box-shadow 0.15s;
    display: flex;
    flex-direction: column;
}

.card:hover {
    border-color: var(--accent);
    box-shadow: var(--shadow-md);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.5rem;
}

.card-tag {
    background: var(--bg-tertiary);
    color: var(--text-tertiary);
    padding: 0.2rem 0.7rem;
    border-radius: 30px;
    font-size: 0.65rem;
    font-weight: 500;
    border: 1px solid var(--border-secondary);
    text-transform: lowercase;
}

.icon-accent {
    color: var(--accent);
    font-size: 1.2rem;
    opacity: 0.9;
}

.card p {
    font-size: 0.95rem;
    color: var(--text-tertiary);
    margin-bottom: var(--spacing-sm);
    flex: 1;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 0.5rem 0;
}

.tech-tag {
    background: var(--bg-primary);
    color: var(--text-tertiary);
    font-size: 0.65rem;
    padding: 0.2rem 0.8rem;
    border-radius: 30px;
    border: 1px solid var(--border-primary);
    font-weight: 450;
}

.github-link {
    margin-top: 0.7rem;
    font-size: 0.8rem;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--accent);
    font-family: 'JetBrains Mono', monospace;
}

.footer {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-primary);
    display: flex;
    justify-content: space-between;
    color: var(--text-tertiary);
    font-size: 0.85rem;
    flex-wrap: wrap;
}

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

.footer-links a {
    color: var(--text-tertiary);
    font-size: 0.85rem;
}

.footer-links a:hover {
    color: var(--accent);
    text-decoration: none;
}

.copy-email {
    cursor: pointer;
}

.about-grid {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: var(--spacing-xl);
    margin: var(--spacing-lg) 0 var(--spacing-xl);
}

.about-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.about-avatar {
    background: linear-gradient(145deg, var(--bg-secondary), var(--bg-tertiary));
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    display: flex;
    justify-content: center;
    align-items: center;
    border: 1px solid var(--border-primary);
}

.avatar-placeholder {
    width: 120px;
    height: 120px;
    background: var(--accent-soft);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--accent);
}

.avatar-placeholder i {
    font-size: 3rem;
    color: var(--accent);
}

.about-contact-card,
.about-languages-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
}

.about-contact-card h4,
.about-languages-card h4 {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-tertiary);
    margin-bottom: var(--spacing-sm);
    font-family: 'JetBrains Mono', monospace;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    padding: 0.6rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border-primary);
    text-decoration: none;
}

.contact-item:last-child {
    border-bottom: none;
}

.contact-item i {
    width: 20px;
    color: var(--accent);
}

.contact-item:hover {
    color: var(--accent);
    text-decoration: none;
}

.language-item {
    margin-bottom: var(--spacing-sm);
}

.language-name {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.3rem;
    font-size: 0.9rem;
}

.language-level {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    color: var(--accent);
}

.language-progress {
    height: 4px;
    background: var(--border-primary);
    border-radius: 2px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
}

.about-main {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.about-name-wrapper {
    margin-bottom: var(--spacing-xs);
}

.about-badge {
    display: inline-block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent);
    background: var(--accent-soft);
    padding: 0.2rem 0.8rem;
    border-radius: 30px;
    border: 1px solid rgba(9,105,218,0.2);
    margin-bottom: 0.5rem;
}

.about-name {
    font-size: 2.8rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 0.25rem;
}

.about-location {
    font-size: 1.1rem;
    color: var(--text-tertiary);
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-bottom: var(--spacing-md);
}

.about-section {
    margin-bottom: var(--spacing-lg);
}

.about-section h3 {
    margin-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--border-primary);
    padding-bottom: 0.3rem;
}

.about-text {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.7;
}

.about-paragraph {
    margin-bottom: 1.2rem;
}

.about-highlight-box {
    background: var(--bg-primary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    padding: 1.2rem;
    display: flex;
    gap: 1rem;
    margin: 1.5rem 0;
}

.highlight-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: var(--accent-soft);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.highlight-icon i {
    font-size: 1.2rem;
    color: var(--accent);
}

.highlight-content p {
    margin-bottom: 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.highlight-content strong {
    display: block;
    margin-bottom: 0.3rem;
    color: var(--text-primary);
}

.about-stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: var(--spacing-lg) 0;
    max-width: 100%;
}

.stat-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    padding: 1rem;
    text-align: center;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent);
    line-height: 1;
    margin-bottom: 0.2rem;
}

.skills-detailed-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.skill-category {
    background: var(--bg-primary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    padding: 1rem;
}

.skill-category-title {
    font-weight: 600;
    margin-bottom: 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    font-size: 0.75rem;
    padding: 0.2rem 0.8rem;
    border-radius: 30px;
    font-family: 'JetBrains Mono', monospace;
}

.education-timeline {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.education-item {
    display: grid;
    grid-template-columns: 50px 1fr;
    gap: 0.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-primary);
    align-items: baseline;
}

.education-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.education-year {
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent);
    font-weight: 600;
    font-size: 0.9rem;
    white-space: nowrap;
}

.education-content {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
}

.education-title {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.education-desc {
    color: var(--text-tertiary);
    font-size: 0.85rem;
}

.interests-grid.three-items {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    max-width: 100%;
}

.interest-item {
    background: var(--bg-primary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    padding: 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    text-align: center;
}

.interest-item i {
    font-size: 1.3rem;
    color: var(--accent);
}

.interest-item span {
    font-family: 'JetBrains Mono', 'SF Mono', monospace;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-tertiary);
    font-weight: 500;
    margin-top: 0.25rem;
}

@media (max-width: 900px) {
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .about-sidebar {
        max-width: 400px;
        margin: 0 auto;
    }
}

@media (max-width: 700px) {
    h1 { font-size: 2.3rem; }
    .hero { flex-direction: column; }
    .hero-main { max-width: 100%; }
    .navbar { flex-direction: column; gap: var(--spacing-sm); }
    .nav-links { flex-wrap: wrap; justify-content: center; }
    .timeline-item { flex-direction: column; }
    .timeline-left { margin-bottom: 0.3rem; }
    
    .about-stats-grid,
    .interests-grid.three-items {
        grid-template-columns: 1fr;
    }
    
    .education-item {
        grid-template-columns: 1fr;
        gap: 0.2rem;
    }
    
    .about-name {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .about-stats-grid,
    .interests-grid.three-items {
        grid-template-columns: 1fr;
    }
}