:root {
    --bg-primary: #e5e5e5;
    --bg-secondary: #d4d4d4;
    --bg-card: #f5f5f5;
    --text-primary: #171717;
    --text-secondary: #404040;
    --text-muted: #737373;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --border: #c4c4c4;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 16px;
}

/* Navigation */
.site-nav {
    position: sticky;
    top: 0;
    background: rgba(229, 229, 229, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
}

.nav-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    transition: color 0.2s ease;
}

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

/* Main Content */
.main-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

.container {
    max-width: 680px;
    margin: 0 auto;
    padding: 2rem 0;
}

/* Header */
.header {
    margin-bottom: 4rem;
}

.avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin-bottom: 1.5rem;
    border: 2px solid var(--border);
}

.avatar-large {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    margin-bottom: 1.5rem;
    border: 2px solid var(--border);
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
}

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

.social-links a {
    color: var(--text-muted);
    transition: color 0.2s ease;
}

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

/* Sections */
section {
    margin-bottom: 4rem;
}

h2 {
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

/* About */
.about-content p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.about-content p:last-child {
    margin-bottom: 0;
}

/* About Page */
.about-page {
    max-width: 680px;
}

.about-header {
    margin-bottom: 3rem;
}

.about-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.role {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

.about-page .about-content h2 {
    font-size: 1.25rem;
    text-transform: none;
    letter-spacing: normal;
    color: var(--text-primary);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

.about-page .education-list {
    list-style: none;
    padding: 0;
}

.about-page .education-list li {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.about-page .education-list strong {
    color: var(--text-primary);
}

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

.about-page a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* Projects */
.project-grid {
    display: grid;
    gap: 1rem;
}

.project-card {
    display: block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    text-decoration: none;
    transition: border-color 0.2s ease, transform 0.2s ease;
}

.project-card:hover {
    border-color: var(--text-muted);
    transform: translateY(-2px);
}

.project-card h3 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.project-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.tech-tag {
    display: inline-block;
    font-size: 0.75rem;
    color: var(--accent);
    background: rgba(37, 99, 235, 0.1);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
}

/* Education */
.education-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.education-item h3 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.education-item p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.year {
    font-size: 0.8125rem;
    color: var(--text-muted);
}

/* Blog */
.blog-container {
    max-width: 680px;
}

.blog-container h1 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

.posts-list {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.post-preview {
    padding-bottom: 2.5rem;
    border-bottom: 1px solid var(--border);
}

.post-preview:last-child {
    border-bottom: none;
}

.post-preview h2,
.post-preview h3 {
    font-size: 1.25rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-transform: none;
    letter-spacing: normal;
    color: var(--text-primary);
}

.post-preview h2 a,
.post-preview h3 a {
    color: var(--text-primary);
    text-decoration: none;
}

.post-preview h2 a:hover,
.post-preview h3 a:hover {
    color: var(--accent);
}

.post-meta {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.post-preview .excerpt,
.post-preview p {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.read-more,
.view-all {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.9375rem;
}

.read-more:hover,
.view-all:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

.no-posts {
    color: var(--text-muted);
    font-style: italic;
}

/* Recent Posts Section */
.recent-posts {
    margin-top: 4rem;
}

/* Intro Section */
.intro {
    margin-bottom: 3rem;
}

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

.recent-posts .posts-list {
    gap: 1.5rem;
}

.recent-posts .post-preview {
    padding-bottom: 1.5rem;
}

/* Post Page */
.post {
    max-width: 680px;
}

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

.post-title {
    font-size: 2rem;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.post-content {
    color: var(--text-secondary);
}

.post-content h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    text-transform: none;
    letter-spacing: normal;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

.post-content h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-top: 2rem;
    margin-bottom: 0.75rem;
}

.post-content p {
    margin-bottom: 1.25rem;
}

.post-content ul,
.post-content ol {
    margin-bottom: 1.25rem;
    padding-left: 1.5rem;
}

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

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

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

.post-content code {
    background: var(--bg-card);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
}

.post-content pre {
    background: var(--bg-card);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: 1.25rem;
}

.post-content pre code {
    background: none;
    padding: 0;
}

.post-content blockquote {
    border-left: 3px solid var(--accent);
    padding-left: 1rem;
    margin: 1.5rem 0;
    font-style: italic;
    color: var(--text-muted);
}

.post-tags {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
}

.tag {
    display: inline-block;
    color: var(--accent);
    font-size: 0.875rem;
    margin-right: 0.75rem;
}

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

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

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

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin-top: 3rem;
}

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

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

.page-number {
    color: var(--text-muted);
}

/* Footer */
.site-footer {
    margin-top: 4rem;
    padding: 2rem 1.5rem;
    border-top: 1px solid var(--border);
    text-align: center;
}

.site-footer .social-links {
    justify-content: center;
    margin-bottom: 1rem;
}

.site-footer p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

footer p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Callout Boxes */
.callout {
    padding: 1rem 1.25rem;
    border-radius: 8px;
    margin: 1.5rem 0;
    border-left: 4px solid;
}

.callout-tip {
    background: rgba(37, 99, 235, 0.08);
    border-color: var(--accent);
}

.callout-note {
    background: rgba(120, 113, 108, 0.08);
    border-color: var(--text-muted);
}

.callout p {
    margin: 0;
    color: var(--text-secondary);
}

.callout strong {
    color: var(--text-primary);
}

/* Architecture Diagram */
.architecture-diagram {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 2rem;
    margin: 1.5rem 0;
    font-family: 'SF Mono', 'Fira Code', monospace;
    overflow-x: auto;
}

.architecture-diagram table {
    margin: 0 auto;
    border-collapse: collapse;
}

.architecture-diagram td {
    padding: 0;
    text-align: center;
    vertical-align: middle;
}

.architecture-diagram .box {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    padding: 0.75rem 1.25rem;
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 0.875rem;
    white-space: nowrap;
}

.architecture-diagram .arrow {
    color: var(--accent);
    font-size: 1.25rem;
    padding: 0 0.75rem;
}

.architecture-diagram .label {
    font-size: 0.75rem;
    color: var(--text-muted);
    padding-top: 0.5rem;
}

/* Responsive */
@media (max-width: 640px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        gap: 1.5rem;
    }

    .main-content {
        padding: 1.5rem 1rem;
    }

    .container {
        padding: 1.5rem 0;
    }

    .header h1 {
        font-size: 2rem;
    }

    .post-title {
        font-size: 1.75rem;
    }

    section {
        margin-bottom: 3rem;
    }
}