:root {
    --primary-color: #2d3748;
    --secondary-color: #4a5568;
    --accent-color: #4299e1;
    --background-color: #ffffff;
    --text-color: #1a202c;
    --border-color: #e2e8f0;
    --card-background: #f7fafc;
    --tag-background: #edf2f7;
    /* Visualization specific variables */
    --nav-bg: var(--card-background);
    --nav-border: var(--border-color);
    --bg-color: var(--background-color);
    --link-color: var(--accent-color);
    --link-hover: #3182ce;
    --active-link: #2b6cb0;
}

[data-theme="dark"] {
    --primary-color: #e2e8f0;
    --secondary-color: #a0aec0;
    --accent-color: #63b3ed;
    --background-color: #1a202c;
    --text-color: #f7fafc;
    --border-color: #2d3748;
    --card-background: #2d3748;
    --tag-background: #4a5568;
    /* Visualization specific variables */
    --nav-bg: var(--card-background);
    --nav-border: var(--border-color);
    --bg-color: var(--background-color);
    --link-color: var(--accent-color);
    --link-hover: #4299e1;
    --active-link: #63b3ed;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.nav-brand a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-color);
}

#theme-toggle {
    background: none;
    border: none;
    color: var(--secondary-color);
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.5rem;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 0;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.subtitle {
    font-size: 1.25rem;
    color: var(--secondary-color);
}

/* Posts Grid */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.post-card {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 8px;
    transition: transform 0.3s;
}

.post-card:hover {
    transform: translateY(-5px);
}

.post-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.post-card h3 {
    margin-bottom: 1rem;
}

.post-card h3 a {
    color: var(--primary-color);
    text-decoration: none;
}

.post-card h3 a:hover {
    color: var(--accent-color);
}

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

.tag {
    background: var(--tag-background);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
    color: var(--secondary-color);
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.project-card {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 8px;
}

.project-card h3 a {
    color: var(--primary-color);
    text-decoration: none;
}

.project-card h3 a:hover {
    color: var(--accent-color);
}

.github-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent-color);
    text-decoration: none;
    margin-top: 1rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
    border-top: 1px solid var(--border-color);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.social-links a {
    color: var(--secondary-color);
    font-size: 1.5rem;
    transition: color 0.3s;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .posts-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }
}

/* Blog Post Styles */
.post-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.post-header {
    margin-bottom: 2rem;
}

.post-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.post-body {
    font-size: 1.125rem;
    line-height: 1.8;
}

.post-body h2 {
    font-size: 1.75rem;
    margin: 2rem 0 1rem;
    color: var(--primary-color);
}

.post-body p {
    margin-bottom: 1.5rem;
}

.post-body img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 2rem 0;
}

.post-body pre {
    background: var(--card-background);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1.5rem 0;
}

.post-body code {
    font-family: 'Fira Code', monospace;
    font-size: 0.9em;
}

.post-body blockquote {
    border-left: 4px solid var(--accent-color);
    padding-left: 1rem;
    margin: 1.5rem 0;
    color: var(--secondary-color);
}

.post-body ul {
    margin: 1.5rem 0;
    padding-left: 1.5rem;
}

.post-body li {
    margin-bottom: 0.5rem;
}

.post-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

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

.post-navigation a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    .post-content {
        padding: 1rem;
    }
    
    .post-header h1 {
        font-size: 2rem;
    }
    
    .post-body {
        font-size: 1rem;
    }
}

/* Writing Page Styles */
.writing-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.writing-content h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.tag-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.tag-filter {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--card-background);
    color: var(--secondary-color);
    cursor: pointer;
    transition: all 0.3s;
}

.tag-filter:hover,
.tag-filter.active {
    background: var(--link-color);
    color: white;
    border-color: var(--link-color);
}

.posts-list {
    display: grid;
    gap: 2rem;
}

.post-card {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 8px;
    transition: transform 0.3s;
}

.post-card:hover {
    transform: translateY(-2px);
}

.post-meta {
    display: flex;
    gap: 1rem;
    color: var(--secondary-color);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.post-card h2 {
    font-size: 1.5rem;
    margin: 0.5rem 0;
}

.post-card h2 a {
    color: var(--primary-color);
    text-decoration: none;
}

.post-card h2 a:hover {
    color: var(--link-color);
}

.post-card p {
    color: var(--secondary-color);
    margin: 1rem 0;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.tag {
    background: var(--tag-background);
    color: var(--secondary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .writing-content {
        padding: 1rem;
    }

    .writing-content h1 {
        font-size: 2rem;
    }

    .post-card {
        padding: 1rem;
    }
}

/* Projects Page Styles */
.projects-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 0;
}

.projects-header {
    text-align: center;
    margin-bottom: 3rem;
}

.project-card {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 8px;
    transition: transform 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.project-status {
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
}

.project-status.active {
    background: #48bb78;
    color: white;
}

.project-status.completed {
    background: #4299e1;
    color: white;
}

.project-status.contribution {
    background: #9f7aea;
    color: white;
}

.project-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 1rem 0;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-links a {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent-color);
    text-decoration: none;
}

.project-links a:hover {
    text-decoration: underline;
}

/* About Page Styles */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.about-hero {
    text-align: center;
    margin-bottom: 4rem;
}

.about-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

.about-actions a {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    text-decoration: none;
    transition: all 0.3s;
}

.resume-link {
    background: var(--accent-color);
    color: white;
}

.contact-link {
    background: var(--card-background);
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

.about-section {
    margin-bottom: 4rem;
}

.timeline {
    position: relative;
    padding-left: 2rem;
}

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

.timeline-item {
    position: relative;
    padding-bottom: 2rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2rem;
    top: 0.5rem;
    width: 1rem;
    height: 1rem;
    border-radius: 50%;
    background: var(--accent-color);
}

.timeline-meta {
    color: var(--secondary-color);
    margin: 0.5rem 0;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-category h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    background: var(--tag-background);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
    color: var(--secondary-color);
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.interest-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--card-background);
    border-radius: 8px;
}

.interest-item i {
    font-size: 2rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.contact-section {
    text-align: center;
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 2rem;
}

.contact-method {
    display: inline-flex;
    align-items: center;
    gap: 1rem;
    color: var(--primary-color);
    text-decoration: none;
    padding: 1rem;
    background: var(--card-background);
    border-radius: 4px;
    transition: all 0.3s;
}

.contact-method:hover {
    background: var(--accent-color);
    color: white;
}

@media (max-width: 768px) {
    .about-actions {
        flex-direction: column;
    }
    
    .skills-grid,
    .interests-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-methods {
        align-items: stretch;
    }
}

.collision-demo {
    padding: 2rem 0;
    text-align: center;
}

.collision-demo .subtitle {
    color: #666;
    margin-bottom: 1.5rem;
}

.collision-container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}