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

:root {
    /* Light Theme Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #1a1a1a;
    --text-secondary: #6c757d;
    --accent: #2c3e50;
    --accent-light: #34495e;
    --border: #e9ecef;
    --shadow: rgba(0, 0, 0, 0.1);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Courier New', monospace;
}

[data-theme="dark"] {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --accent: #58a6ff;
    --accent-light: #79c0ff;
    --border: #30363d;
    --shadow: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Navigation */
#navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
    font-family: var(--font-mono);
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent);
    transition: width 0.3s ease;
}

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

.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    font-size: 1.2rem;
}

.theme-toggle:hover {
    border-color: var(--accent);
    transform: rotate(15deg);
}

[data-theme="light"] .moon-icon {
    display: none;
}

[data-theme="dark"] .sun-icon {
    display: none;
}

/* Sections */
.section {
    padding: var(--spacing-xl) 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

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

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--accent);
    margin: var(--spacing-sm) auto 0;
    border-radius: 2px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    padding-top: 80px;
}

.hero-content {
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    display: inline-block;
    border: 2px solid transparent;
}

.btn-primary {
    background-color: var(--accent);
    color: white;
}

.btn-primary:hover {
    background-color: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent);
    border-color: var(--accent);
}

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

/* About Section */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.highlight-item {
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: 12px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.highlight-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px var(--shadow);
}

.highlight-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: var(--spacing-xs);
}

.highlight-label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Timeline */
.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding-left: 40px;
}

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-lg);
    animation: fadeInLeft 0.6s ease-out;
}

.timeline-marker {
    position: absolute;
    left: -46px;
    top: 0;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--accent);
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 3px var(--accent);
}

.timeline-content {
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.timeline-content:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 12px var(--shadow);
}

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

.timeline-header h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
}

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

.company {
    color: var(--accent);
    font-size: 1.1rem;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.timeline-list {
    list-style: none;
    padding-left: 0;
}

.timeline-list li {
    padding-left: 1.5rem;
    margin-bottom: var(--spacing-xs);
    position: relative;
    color: var(--text-secondary);
    line-height: 1.7;
}

.timeline-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

/* Skills Section */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    max-width: 1000px;
    margin: 0 auto;
}

.skill-category {
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px var(--shadow);
}

.skill-category-title {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

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

.skill-tag {
    padding: 0.5rem 1rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all 0.3s ease;
}

.skill-tag:hover {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
    transform: scale(1.05);
}

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

.contact-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.contact-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-sm);
}

.contact-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.contact-link:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px var(--shadow);
    border-color: var(--accent);
}

.contact-icon {
    font-size: 1.5rem;
}

/* Footer */
.footer {
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-secondary);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

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

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

    .section-title {
        font-size: 2rem;
    }

    .timeline {
        padding-left: 30px;
    }

    .timeline-marker {
        left: -36px;
    }

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

    .contact-links {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-md: 1rem;
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .about-highlights {
        grid-template-columns: 1fr;
    }

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