/* CSS Variables & Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-blue: #2563eb;
    --primary-blue-dark: #1d4ed8;
    --primary-blue-light: #3b82f6;
    --orange: #f97316;
    --orange-hover: #ea580c;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-400: #9ca3af;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-900: #111827;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-dark: #111827;
    --max-width: 1280px;
    --content-width: 800px;
    --nav-height: 72px;
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-900);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; height: auto; }

/* Navigation */
.site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid rgba(229, 231, 235, 0.5);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: opacity 0.2s;
}

.logo:hover { opacity: 0.8; }

.logo-icon {
    width: 2rem;
    height: 2rem;
    color: var(--primary-blue);
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    color: var(--gray-600);
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover { color: var(--gray-900); }

.btn-signup {
    background-color: var(--orange);
    color: white !important;
    padding: 0.5rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    transition: all 0.2s;
}

.btn-signup:hover {
    background-color: var(--orange-hover);
    box-shadow: 0 4px 12px rgba(249, 115, 22, 0.3);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.menu-icon {
    width: 1.5rem;
    height: 1.5rem;
    color: var(--gray-600);
}

.mobile-menu {
    display: none;
    background-color: white;
    border-top: 1px solid var(--gray-200);
    padding: 1rem;
}

.mobile-menu.active {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* Main Content */
.main-content {
    margin-top: var(--nav-height);
    padding: 4rem 1.5rem;
    background-color: var(--bg-light);
    min-height: calc(100vh - var(--nav-height));
}

.article-container {
    max-width: var(--content-width);
    margin: 0 auto;
    background-color: white;
    padding: 3rem;
    border-radius: 1rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

/* Article Header */
.article-header {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: none;
}

.article-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

.article-category {
    color: var(--primary-blue);
    font-weight: 600;
}

.article-header h1 {
    font-size: 2.5rem;
    line-height: 1.2;
    color: var(--gray-900);
    margin-bottom: 1rem;
    font-weight: 800;
}

.article-subtitle {
    font-size: 1.25rem;
    color: var(--gray-600);
    line-height: 1.6;
}

/* Article Content */
.article-content {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--gray-700);
}

.article-content .lead {
    font-size: 1.25rem;
    color: var(--gray-900);
    margin-bottom: 2rem;
    font-weight: 500;
    line-height: 1.7;
}

.article-content h2 {
    font-size: 2rem;
    color: var(--gray-900);
    margin-top: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.article-content h3 {
    font-size: 1.5rem;
    color: var(--gray-900);
    margin-top: 2rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
}

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

.article-content ul, .article-content ol {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
}

.article-content li {
    margin-bottom: 0.5rem;
}

.article-content blockquote {
    margin: 2rem 0;
    padding: 1.5rem 2rem;
    border-left: 4px solid var(--primary-blue);
    background: linear-gradient(to right, rgba(37, 99, 235, 0.05), transparent);
    border-radius: 0.25rem;
}

.article-content blockquote p {
    margin: 0;
    font-size: 1.25rem;
    font-style: italic;
    color: var(--gray-900);
}

.article-content code {
    background-color: var(--gray-100);
    padding: 0.2rem 0.4rem;
    border-radius: 0.25rem;
    font-family: 'Monaco', monospace;
    font-size: 0.9em;
}

.article-content pre {
    background-color: var(--gray-900);
    color: #f8f8f2;
    padding: 1.5rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin: 2rem 0;
}

.article-content pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.article-content .info-box {
    background-color: rgba(37, 99, 235, 0.05);
    border-left: 4px solid var(--primary-blue);
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 0.25rem;
}

.article-content .info-box h4 {
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

/* Article Footer */
.article-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.tag {
    background-color: var(--gray-100);
    color: var(--gray-700);
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.875rem;
    font-weight: 500;
}

.article-share {
    display: flex;
    gap: 1rem;
    align-items: center;
    color: var(--gray-600);
    font-size: 0.9rem;
}

.share-link {
    color: var(--primary-blue);
    font-weight: 600;
    transition: color 0.2s;
}

.share-link:hover {
    color: var(--primary-blue-dark);
}

/* Footer CTA */
.footer-cta-section {
    background: linear-gradient(to right, var(--primary-blue), var(--primary-blue-dark));
    padding: 3rem 1.5rem;
}

.footer-cta-container {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
    color: white;
}

.footer-cta-container h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-cta-container p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
}

.btn-cta {
    display: inline-block;
    background-color: var(--orange);
    color: white;
    padding: 1rem 2rem;
    border-radius: 0.75rem;
    font-weight: 600;
    font-size: 1.125rem;
    transition: all 0.2s;
}

.btn-cta:hover {
    background-color: var(--orange-hover);
    box-shadow: 0 8px 24px rgba(249, 115, 22, 0.4);
    transform: scale(1.05);
}

/* Footer */
.site-footer {
    background-color: var(--bg-dark);
    color: var(--gray-400);
    padding: 4rem 1.5rem 2rem;
}

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

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand .footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.footer-brand .footer-logo svg {
    width: 2rem;
    height: 2rem;
    color: var(--primary-blue-light);
}

.footer-brand .footer-logo span {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
}

.footer-description {
    max-width: 500px;
    line-height: 1.6;
}

.footer-column h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: white;
}

.footer-column ul {
    list-style: none;
    padding: 0;
}

.footer-column li { margin-bottom: 0.75rem; }

.footer-column a {
    color: var(--gray-400);
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-column a:hover { color: white; }

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: var(--gray-400);
    font-size: 0.875rem;
    transition: color 0.2s;
}

.footer-links a:hover { color: white; }

/* Responsive */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .mobile-menu-btn { display: block; }
    
    .article-container {
        padding: 2rem 1.5rem;
    }
    
    .article-header h1 {
        font-size: 2rem;
    }
    
    .article-subtitle {
        font-size: 1.125rem;
    }
    
    .article-content {
        font-size: 1rem;
    }
    
    .article-content .lead {
        font-size: 1.125rem;
    }
    
    .article-content h2 {
        font-size: 1.5rem;
    }
    
    .article-content h3 {
        font-size: 1.25rem;
    }
    
    .article-footer {
        flex-direction: column;
        gap: 1.5rem;
        align-items: flex-start;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}