:root {
    --primary: #1D3557;
    --primary-dark: #14263F;
    --secondary: #2A4A6E;
    --text-dark: #1a1a2e;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --bg-soft: #f8f9ff;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-dark);
    background: #ffffff;
    line-height: 1.7;
}

.blog-nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 5%;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(8px);
    z-index: 100;
}

.blog-nav a.brand {
    font-weight: 800;
    font-size: 1.3rem;
    color: var(--text-dark);
    text-decoration: none;
}

.blog-nav .nav-actions a {
    margin-left: 20px;
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
}

.blog-nav .nav-actions a.cta {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
}

.blog-hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 60px 5% 50px;
    text-align: center;
}

.blog-hero h1 {
    font-size: 2.4rem;
    margin: 0 0 12px;
}

.blog-hero p {
    font-size: 1.15rem;
    opacity: 0.92;
    max-width: 640px;
    margin: 0 auto;
}

.blog-list {
    max-width: 900px;
    margin: 0 auto;
    padding: 50px 5% 80px;
    display: grid;
    gap: 28px;
}

.post-card {
    display: block;
    text-decoration: none;
    color: inherit;
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 28px;
    transition: box-shadow 0.2s, transform 0.2s;
}

.post-card:hover {
    box-shadow: 0 12px 30px rgba(102, 126, 234, 0.15);
    transform: translateY(-2px);
}

.post-card .tag {
    display: inline-block;
    background: var(--bg-soft);
    color: var(--primary-dark);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 12px;
}

.post-card h2 {
    margin: 0 0 10px;
    font-size: 1.4rem;
    color: var(--text-dark);
}

.post-card p.excerpt {
    color: var(--text-muted);
    margin: 0 0 14px;
    font-size: 0.98rem;
}

.post-card .meta {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.post-article {
    max-width: 740px;
    margin: 0 auto;
    padding: 50px 5% 80px;
}

.post-article .tag {
    display: inline-block;
    background: var(--bg-soft);
    color: var(--primary-dark);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 16px;
}

.post-article h1 {
    font-size: 2.1rem;
    line-height: 1.3;
    margin: 0 0 12px;
}

.post-article .meta {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border);
}

.post-article h2 {
    font-size: 1.5rem;
    margin-top: 40px;
    color: var(--text-dark);
}

.post-article h3 {
    font-size: 1.2rem;
    margin-top: 28px;
}

.post-article p, .post-article li {
    font-size: 1.05rem;
    color: #333;
}

.post-article ul, .post-article ol {
    padding-left: 22px;
}

.post-article a {
    color: var(--primary-dark);
}

.citation-box {
    background: var(--bg-soft);
    border-left: 4px solid var(--primary);
    padding: 16px 20px;
    border-radius: 8px;
    font-size: 0.92rem;
    margin: 28px 0;
}

.disclaimer-box {
    background: #fff8ec;
    border-left: 4px solid #e0a800;
    padding: 16px 20px;
    border-radius: 8px;
    font-size: 0.92rem;
    margin: 28px 0;
    color: #6b5000;
}

.post-cta {
    margin-top: 48px;
    padding: 32px;
    text-align: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: 16px;
    color: white;
}

.post-cta h3 { margin: 0 0 8px; }
.post-cta p { color: rgba(255,255,255,0.9); margin: 0 0 18px; }

.post-cta a.btn {
    display: inline-block;
    background: white;
    color: var(--primary-dark);
    padding: 12px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
}

.related-links {
    margin-top: 40px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.related-links h4 { margin-bottom: 10px; }

.blog-footer {
    text-align: center;
    padding: 30px 5%;
    color: var(--text-muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--border);
}

@media (max-width: 640px) {
    .blog-hero h1 { font-size: 1.8rem; }
    .post-article h1 { font-size: 1.6rem; }
}