:root {
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-text-secondary: #666666;
    --color-border: #e5e5e5;
    --color-accent: #2563eb;
    --color-accent-hover: #1d4ed8;
    --color-section-alt: #f9fafb;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;
    --max-width: 900px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
    font-size: 16px;
}

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

/* Navigation */
.nav {
    position: sticky;
    top: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
    list-style: none;
}

.nav-menu a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

.nav-menu a:hover {
    color: var(--color-accent);
}

/* Hero Section */
.hero {
    padding: var(--spacing-xl) 0;
    min-height: 60vh;
    display: flex;
    align-items: center;
}

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

.hero-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--color-border);
    flex-shrink: 0;
}

.hero-text {
    flex: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.hero-location {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.hero-links {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.hero-links a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.hero-links a:hover {
    color: var(--color-accent-hover);
}

/* Sections */
.section {
    padding: var(--spacing-xl) 0;
}

.section-alt {
    background-color: var(--color-section-alt);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.01em;
}

/* About */
.about-text {
    font-size: 1.2rem;
    line-height: 1.8;
    color: var(--color-text-secondary);
    max-width: 700px;
}

/* Timeline (Experience & Education) */
.timeline {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.timeline-item {
    position: relative;
    padding-left: var(--spacing-md);
    border-left: 2px solid var(--color-border);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 0;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--color-accent);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: var(--spacing-xs);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.timeline-position {
    font-size: 1.3rem;
    font-weight: 600;
}

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

.timeline-company {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.timeline-location {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.timeline-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.7;
}

.timeline-highlights {
    list-style: none;
    margin-bottom: var(--spacing-sm);
}

.timeline-highlights li {
    padding-left: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
    position: relative;
    color: var(--color-text-secondary);
}

.timeline-highlights li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--color-accent);
}

.timeline-technologies {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.tech-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--color-bg);
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    border-radius: 1rem;
    font-size: 0.85rem;
    font-family: var(--font-mono);
}

.section-alt .tech-tag {
    background-color: #ffffff;
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.skill-category {
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    background-color: var(--color-bg);
}

.skill-category-name {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

/* Awards */
.awards-section {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.awards-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

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

.award-item {
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    background-color: var(--color-bg);
}

.award-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.award-meta {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.award-description {
    color: var(--color-text-secondary);
    line-height: 1.7;
}

/* Contact */
.contact-info {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-text {
    font-size: 1.2rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.contact-link {
    font-size: 1.1rem;
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

.contact-link:hover {
    color: var(--color-accent-hover);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.social-links a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 1rem;
    transition: color 0.2s ease;
}

.social-links a:hover {
    color: var(--color-accent);
}

/* Footer */
.footer {
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--color-border);
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

.footer-note {
    margin-top: var(--spacing-xs);
}

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

.footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }

    .hero-image {
        width: 150px;
        height: 150px;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-links {
        justify-content: center;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .nav-menu {
        display: none;
    }

    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }
}