:root {
    --bg-primary: #0c0c0c;
    --bg-secondary: #141414;
    --bg-tertiary: #1a1a1a;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent: #2d8f4e;
    --accent-dim: #3cb371;
    --border: #2a2a2a;
    --border-subtle: #222222;
    --code-bg: #1a1a1a;
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', Consolas, 'Liberation Mono', Menlo, monospace;
    --max-width: 68ch;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.75rem;
    --spacing-xl: 3rem;
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 400ms ease;
}

@media (prefers-color-scheme: light) {
    :root {
        --bg-primary: #fafafa;
        --bg-secondary: #f5f5f5;
        --bg-tertiary: #ebebeb;
        --text-primary: #1a1a1a;
        --text-secondary: #525252;
        --text-muted: #888888;
        --accent: #2d8f4e;
        --accent-dim: #3cb371;
        --border: #e5e5e5;
        --border-subtle: #eeeeee;
        --code-bg: #f0f0f0;
    }
}

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

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-md);
    background: var(--accent);
    color: var(--bg-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: 4px;
    z-index: 1000;
    text-decoration: none;
    font-weight: 600;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: var(--spacing-md);
}

/* Header */
.site-header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-subtle);
    padding: var(--spacing-md) var(--spacing-lg);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
    background: rgba(12, 12, 12, 0.9);
}

@media (prefers-color-scheme: light) {
    .site-header {
        background: rgba(250, 250, 250, 0.9);
    }
}

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

.site-logo {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
    letter-spacing: -0.02em;
    transition: color var(--transition-fast);
}

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

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

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width var(--transition-normal);
}

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

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

/* Main Content */
.main-content {
    flex: 1;
    padding: var(--spacing-xl) var(--spacing-lg);
}

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

/* Page Titles */
.page-title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    margin-bottom: var(--spacing-xl);
    color: var(--text-primary);
}

/* Post List */
.post-list {
    list-style: none;
}

.post-item {
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--border-subtle);
    animation: fadeIn 0.4s ease backwards;
}

.post-item:first-child {
    padding-top: 0;
}

.post-item:nth-child(1) { animation-delay: 0ms; }
.post-item:nth-child(2) { animation-delay: 50ms; }
.post-item:nth-child(3) { animation-delay: 100ms; }
.post-item:nth-child(4) { animation-delay: 150ms; }
.post-item:nth-child(5) { animation-delay: 200ms; }

.post-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    letter-spacing: -0.01em;
}

.post-title a {
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.post-meta {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: var(--spacing-sm);
}

.tag {
    color: var(--text-muted);
    font-weight: 400;
    text-decoration: none;
}

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

.footer-rss {
    color: var(--text-muted);
    padding: 0 0.25rem;
}

.footer-rss:hover {
    color: var(--accent);
}

.post-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Post/Page Full */
.post-full, .page-content {
    max-width: var(--max-width);
    margin: 0 auto;
}

.post-header, .page-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-subtle);
}

.post-header .post-title {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.post-meta-full {
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    font-size: 0.9rem;
}

/* Content Typography */
.post-content, .markdown-body {
    line-height: 1.75;
}

.post-content h1, .post-content h2, .post-content h3,
.markdown-body h1, .markdown-body h2, .markdown-body h3 {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.post-content h1, .markdown-body h1 { font-size: 1.75rem; }
.post-content h2, .markdown-body h2 { font-size: 1.4rem; }
.post-content h3, .markdown-body h3 { font-size: 1.15rem; }

.post-content p, .markdown-body p {
    margin-bottom: var(--spacing-md);
}

.post-content a, .markdown-body a {
    color: var(--accent);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-fast), color var(--transition-fast);
}

.post-content a:hover, .markdown-body a:hover {
    border-bottom-color: var(--accent);
}

.post-content code, .markdown-body code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    background: var(--code-bg);
    padding: 2px 6px;
    border-radius: 3px;
}

.post-content pre, .markdown-body pre {
    background: var(--code-bg);
    padding: var(--spacing-md);
    border-radius: 6px;
    overflow-x: auto;
    margin: var(--spacing-lg) 0;
    border: 1px solid var(--border);
}

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

.post-content ul, .post-content ol,
.markdown-body ul, .markdown-body ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

.post-content li, .markdown-body li {
    margin-bottom: var(--spacing-xs);
}

.post-content li::marker {
    color: var(--text-muted);
}

.post-content blockquote, .markdown-body blockquote {
    border-left: 2px solid var(--accent);
    padding-left: var(--spacing-md);
    margin: var(--spacing-lg) 0;
    color: var(--text-secondary);
    font-style: italic;
}

.post-content img, .markdown-body img {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
    margin: var(--spacing-lg) 0;
}

/* Post/Page Navigation */
.post-nav, .page-nav {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-subtle);
}

.post-nav a, .page-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.post-nav a:hover, .page-nav a:hover {
    color: var(--accent);
}

/* Footer */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-subtle);
    padding: var(--spacing-lg);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.site-footer p {
    margin: 0;
}

.sep {
    padding: 0 0.35rem;
    color: var(--text-muted);
}

/* Focus States */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* View Transitions API */
@view-transition {
    navigation: auto;
}

::view-transition-old(root),
::view-transition-new(root) {
    animation-duration: 0.25s;
}

/* Responsive */
@media (max-width: 640px) {
    :root {
        font-size: 15px;
    }
    
    .site-header {
        padding: var(--spacing-md);
    }
    
    .main-content {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .page-title, .post-header .post-title {
        font-size: 1.6rem;
    }
    
    .nav-links {
        gap: var(--spacing-md);
    }
}

/* Tags Page */
.tags-section {
    margin-top: var(--spacing-lg);
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tag-item {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 4px;
    text-decoration: none;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.tag-item:hover {
    background: var(--accent);
    color: var(--bg-primary);
}