:root {
    --bg-color: #f5f5f5;
    --text-color: #333;
    --accent-color: #2563eb;
    --border-color: #e5e7eb;
    --card-bg: #ffffff;
    --text-muted: #666;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #e5e7eb;
    --accent-color: #60a5fa;
    --border-color: #374151;
    --card-bg: #262626;
    --text-muted: #9ca3af;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

.site-header {
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s, border-color 0.3s;
}

.site-header nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s;
}

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

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background-color: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
    transition: background-color 0.2s, border-color 0.2s;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.hero {
    text-align: center;
    padding: 3rem 0;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero .tagline {
    font-size: 1.25rem;
    color: var(--text-muted);
    font-style: italic;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.project-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s, background-color 0.3s, border-color 0.3s;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] .project-card:hover {
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.4);
}

.project-card-link {
    display: block;
    text-decoration: none;
    color: inherit;
}

.project-card-link:hover h2 {
    color: var(--accent-color);
}

.project-image {
    width: 100%;
    height: 250px;
    object-fit: cover;
    display: block;
}

.project-content {
    padding: 1.5rem;
}

.project-content h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    transition: color 0.2s;
}

.project-content time {
    display: block;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

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

.category, .tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--bg-color);
    border-radius: 0.25rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    transition: background-color 0.3s, color 0.3s;
}

.post {
    background-color: var(--card-bg);
    padding: 3rem;
    border-radius: 0.5rem;
    max-width: 800px;
    margin: 2rem auto;
    transition: background-color 0.3s;
}

.post-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    transition: border-color 0.3s;
}

.post-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.post-meta {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.post-meta time {
    margin-right: 1rem;
}

.featured-image {
    width: 100%;
    max-height: 500px;
    object-fit: cover;
    border-radius: 0.5rem;
    margin-bottom: 2rem;
}

.post-content {
    font-size: 1.1rem;
    line-height: 1.8;
}

.post-content img {
    max-width: 100%;
    height: auto;
    border-radius: 0.5rem;
    margin: 2rem 0;
}

.post-content h2 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 1.75rem;
}

.post-content h3 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1.5rem;
}

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

.post-content ul, .post-content ol {
    margin-left: 2rem;
    margin-bottom: 1.5rem;
}

.post-content code {
    background-color: var(--bg-color);
    padding: 0.2rem 0.4rem;
    border-radius: 0.25rem;
    font-size: 0.95em;
    transition: background-color 0.3s;
}

.post-content pre {
    background-color: #282c34;
    color: #abb2bf;
    padding: 1.5rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin-bottom: 1.5rem;
}

.post-content pre code {
    background-color: transparent;
    padding: 0;
}

.post-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    transition: border-color 0.3s;
}

.back-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
}

.back-link:hover {
    text-decoration: underline;
}

.site-footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.9rem;
}

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

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

/* Auth button styling - subtle grayscale */
.auth-btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    background-color: var(--bg-color);
    color: var(--text-color);
    text-decoration: none;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    font-size: 0.875rem;
    font-weight: 500;
    transition: background-color 0.2s, color 0.2s, border-color 0.2s;
}

.auth-btn:hover {
    background-color: var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .post {
        padding: 1.5rem;
    }
    
    .post-header h1 {
        font-size: 2rem;
    }
    
    .header-controls {
        gap: 0.5rem;
    }
    
    .theme-toggle {
        padding: 0.5rem;
        font-size: 1rem;
    }
}