/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --bg: #0f1115;
    --bg-card: #181b21;
    --bg-card-hover: #1e2229;
    --text: #e0e0e0;
    --text-muted: #8a8f98;
    --accent: #4fc3f7;
    --accent-hover: #29b6f6;
    --accent-glow: rgba(79, 195, 247, 0.15);
    --border: #2a2e36;
    --code-bg: #1a1e26;
    --radius: 8px;
    --max-width: 820px;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    font-size: 16px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s;
}
a:hover { color: var(--accent-hover); }

/* === Header === */
.site-header {
    border-bottom: 1px solid var(--border);
    padding: 1.5rem 0;
    background: var(--bg);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
    background: rgba(15, 17, 21, 0.9);
}

.header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.site-logo .logo-icon {
    color: var(--accent);
    font-size: 1.2rem;
}

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

.site-nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.site-nav a {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}
.site-nav a:hover, .site-nav a.active { color: var(--accent); }

/* === Main Content === */
.site-main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2.5rem 1.5rem;
    flex: 1;
    width: 100%;
}

/* === Hero / Page Header === */
.page-hero {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border);
}

.page-hero h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 0.5rem;
}

.page-hero .tagline {
    color: var(--text-muted);
    font-size: 1.05rem;
}

/* === Post Cards (Index) === */
.post-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.post-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: background 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.post-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent);
    box-shadow: 0 0 20px var(--accent-glow);
}

.post-card .post-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-bottom: 0.6rem;
    font-family: var(--font-mono);
}

.post-card h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    letter-spacing: -0.01em;
}

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

.post-card .excerpt {
    color: var(--text-muted);
    font-size: 0.92rem;
    line-height: 1.6;
}

.tag {
    display: inline-block;
    background: rgba(79, 195, 247, 0.1);
    color: var(--accent);
    font-size: 0.75rem;
    padding: 0.15rem 0.5rem;
    border-radius: 3px;
    font-family: var(--font-mono);
    font-weight: 500;
}

/* === Single Post === */
.post-header {
    margin-bottom: 2rem;
}

.post-header h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 0.75rem;
    line-height: 1.3;
}

.post-header .post-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* === Article Content === */
.post-content {
    font-size: 1rem;
    line-height: 1.8;
}

.post-content h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 2.5rem 0 1rem;
    letter-spacing: -0.02em;
    color: var(--text);
}

.post-content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin: 2rem 0 0.75rem;
    color: var(--text);
}

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

.post-content ul, .post-content ol {
    margin: 0 0 1.25rem 1.5rem;
}

.post-content li {
    margin-bottom: 0.3rem;
}

.post-content blockquote {
    border-left: 3px solid var(--accent);
    padding: 0.75rem 1.25rem;
    margin: 1.5rem 0;
    background: var(--accent-glow);
    border-radius: 0 var(--radius) var(--radius) 0;
    color: var(--text-muted);
    font-style: italic;
}

.post-content code {
    background: var(--code-bg);
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.88em;
    color: var(--accent);
}

.post-content pre {
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    overflow-x: auto;
    margin: 1.5rem 0;
    line-height: 1.5;
}

.post-content pre code {
    background: none;
    padding: 0;
    font-size: 0.88rem;
    color: var(--text);
}

.post-content img {
    max-width: 100%;
    border-radius: var(--radius);
    margin: 1.5rem 0;
    border: 1px solid var(--border);
}

.post-content a {
    text-decoration: underline;
    text-underline-offset: 2px;
}

.post-content hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2rem 0;
}

.post-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.92rem;
}

.post-content th, .post-content td {
    border: 1px solid var(--border);
    padding: 0.6rem 0.8rem;
    text-align: left;
}

.post-content th {
    background: var(--code-bg);
    font-weight: 600;
}

/* === Back Link === */
.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    margin-bottom: 2rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}
.back-link:hover { color: var(--accent); }

/* === Tags Page === */
.tags-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.tags-cloud .tag {
    font-size: 0.85rem;
    padding: 0.3rem 0.75rem;
}

.tags-cloud .tag:hover {
    background: rgba(79, 195, 247, 0.2);
}

/* === Footer === */
.site-footer {
    border-top: 1px solid var(--border);
    padding: 1.5rem 0;
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* === 404 === */
.not-found {
    text-align: center;
    padding: 4rem 0;
}

.not-found h1 {
    font-size: 5rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 1rem;
}

.not-found p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* === Responsive === */
@media (max-width: 640px) {
    .page-hero h1 { font-size: 1.5rem; }
    .post-header h1 { font-size: 1.5rem; }
    .post-card { padding: 1.25rem; }
    .header-inner { flex-direction: column; gap: 0.75rem; }
    .site-nav { gap: 1rem; }
}