/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-accent: #f0f0f0;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-muted: #999999;
    --border-color: #e0e0e0;
    --accent-color: #0066cc;
    --accent-hover: #0052a3;
    --success-color: #28a745;
    --spacing-unit: 1rem;
    --max-width: 800px;
    --border-radius: 4px;
    --transition: all 0.3s ease;
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #252525;
    --bg-accent: #2d2d2d;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-muted: #808080;
    --border-color: #404040;
    --accent-color: #4a9eff;
    --accent-hover: #6bb0ff;
}

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

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

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

/* ===========================
   Layout
   =========================== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2rem 1.5rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===========================
   Header
   =========================== */
header {
    margin-bottom: 3rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

header h1 a {
    color: var(--text-primary);
    text-decoration: none;
}

header h1 a:hover {
    color: var(--accent-color);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

nav {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding: 0.25rem 0;
    border-bottom: 2px solid transparent;
}

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

nav a.active {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

/* ===========================
   Main Content
   =========================== */
main {
    flex: 1;
}

/* ===========================
   Post Card
   =========================== */
.post {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.post:hover {
    border-color: var(--accent-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.post-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.post-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

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

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

.post-meta {
    display: flex;
    gap: 1rem;
    color: var(--text-muted);
    font-size: 0.875rem;
    align-items: center;
}

.post-date {
    font-family: var(--font-mono);
}

.post-category {
    background: var(--bg-accent);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.post-category.ideas {
    color: #d97706;
    background: rgba(217, 119, 6, 0.1);
}

.post-category.snapshots {
    color: #059669;
    background: rgba(5, 150, 105, 0.1);
}

.post-category.tech {
    color: #7c3aed;
    background: rgba(124, 58, 237, 0.1);
}

.post-content {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.post-content p {
    margin-bottom: 0.75rem;
}

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

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

.post-content code {
    font-family: var(--font-mono);
    background: var(--bg-accent);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-size: 0.875rem;
}

.post-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    color: var(--text-muted);
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    background: var(--bg-accent);
    border-radius: 3px;
}

/* ===========================
   Post Navigation
   =========================== */
.post-nav {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.post-nav a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
}

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

.post-nav .prev {
    text-align: left;
}

.post-nav .next {
    text-align: right;
    margin-left: auto;
}

/* ===========================
   Footer
   =========================== */
footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

footer a {
    color: var(--text-muted);
    text-decoration: none;
    transition: var(--transition);
}

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

/* ===========================
   Utility Classes
   =========================== */
.hidden {
    display: none !important;
}

/* ===========================
   Empty State
   =========================== */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 600px) {
    header h1 {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    nav {
        gap: 1rem;
    }
    
    .post {
        padding: 1rem;
    }
    
    .post-title {
        font-size: 1.25rem;
    }
    
    .post-header {
        flex-direction: column;
    }
}

/* ===========================
   Animations
   =========================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.post {
    animation: fadeIn 0.3s ease;
}

/* ===========================
   Print Styles
   =========================== */
@media print {
    nav, footer {
        display: none;
    }
    
    .post {
        page-break-inside: avoid;
        border: 1px solid #000;
    }
}