/* MODERN TECHNICAL WIKI DESIGN SYSTEM */
:root {
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --border-color: #e2e8f0;
    --accent-color: #0284c7;
    --accent-hover: #0369a1;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    
    --radius-sm: 6px;
    --radius-md: 12px;
    --max-width: 1200px;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

a { color: inherit; text-decoration: none; transition: color 0.2s ease; }
a:hover { color: var(--accent-color); }
img { max-width: 100%; height: auto; display: block; border-radius: var(--radius-sm); }

.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; }

/* HEADER */
.site-header {
    background: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.logo img { width: 28px; height: 28px; }

.main-nav { display: flex; gap: 2rem; }
.main-nav a { font-size: 0.95rem; font-weight: 500; color: var(--text-secondary); }
.main-nav a:hover, .main-nav a.active { color: var(--accent-color); }

.mobile-toggle { display: none; background: none; border: none; font-size: 1.5rem; color: var(--text-primary); cursor: pointer; }

/* HERO */
.hero { padding: 5rem 0; text-align: center; background: linear-gradient(to bottom, #ffffff, #f8fafc); border-bottom: 1px solid var(--border-color); }
.hero h1 { font-size: 3.5rem; font-weight: 800; letter-spacing: -0.02em; margin-bottom: 1.5rem; color: var(--text-primary); line-height: 1.1; }
.hero p { font-size: 1.25rem; color: var(--text-secondary); max-width: 700px; margin: 0 auto 2.5rem; }
.hero-image-wrap { max-width: 900px; margin: 0 auto; border-radius: var(--radius-md); overflow: hidden; box-shadow: 0 20px 40px -10px rgba(0,0,0,0.1); border: 1px solid var(--border-color); }

.btn {
    display: inline-flex; align-items: center; justify-content: center;
    background: var(--accent-color); color: white; padding: 0.875rem 2rem;
    font-weight: 600; border-radius: var(--radius-sm); transition: background 0.2s;
}
.btn:hover { background: var(--accent-hover); color: white; }

/* GRIDS */
.section { padding: 5rem 0; }
.section-title { font-size: 2rem; font-weight: 700; margin-bottom: 2.5rem; text-align: center; }

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 3rem; }

/* CARDS */
.card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 12px 24px -10px rgba(0,0,0,0.1); border-color: var(--accent-color); }
.card-img { aspect-ratio: 16/9; width: 100%; object-fit: cover; border-radius: 0; border-bottom: 1px solid var(--border-color); }
.card-content { padding: 1.5rem; flex-grow: 1; display: flex; flex-direction: column; }
.card-meta { font-size: 0.875rem; color: var(--text-secondary); margin-bottom: 0.75rem; font-weight: 500; }
.card-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 1rem; line-height: 1.3; }
.card-excerpt { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 1.5rem; }
.card-link { margin-top: auto; font-weight: 600; color: var(--accent-color); }

/* ARTICLE SPECIFIC */
.article-header { text-align: center; margin-bottom: 3rem; max-width: 800px; margin: 0 auto 3rem; }
.article-meta { color: var(--text-secondary); font-weight: 500; margin-bottom: 1rem; }
.article-title { font-size: 2.75rem; font-weight: 800; line-height: 1.2; margin-bottom: 1.5rem; }
.article-lead { font-size: 1.25rem; color: var(--text-secondary); }
.article-content { max-width: 800px; margin: 0 auto; font-size: 1.1rem; line-height: 1.8; color: var(--text-primary); }
.article-content h2 { font-size: 1.875rem; margin: 3rem 0 1.5rem; font-weight: 700; }
.article-content h3 { font-size: 1.5rem; margin: 2rem 0 1rem; font-weight: 600; }
.article-content p { margin-bottom: 1.5rem; }
.article-content ul, .article-content ol { margin: 0 0 1.5rem 1.5rem; padding-left: 1rem; }
.article-content li { margin-bottom: 0.75rem; }
.article-content img { margin: 2.5rem 0; border: 1px solid var(--border-color); box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05); }

.alert-box {
    padding: 1.5rem; border-radius: var(--radius-sm); margin: 2rem 0;
    border-left: 4px solid var(--accent-color); background: var(--bg-color);
}
.alert-box.danger { border-left-color: var(--danger-color); background: #fef2f2; }
.alert-box.warning { border-left-color: var(--warning-color); background: #fffbeb; }
.alert-box h4 { margin-top: 0; margin-bottom: 0.5rem; font-size: 1.1rem; }

/* BREADCRUMBS */
.breadcrumbs { padding: 1.5rem 0; font-size: 0.9rem; color: var(--text-secondary); }
.breadcrumbs a { color: var(--text-secondary); }
.breadcrumbs a:hover { color: var(--accent-color); }
.breadcrumbs span { margin: 0 0.5rem; }

/* FORMS */
.form-group { margin-bottom: 1.5rem; }
.form-label { display: block; margin-bottom: 0.5rem; font-weight: 500; }
.form-control { width: 100%; padding: 0.875rem; border: 1px solid var(--border-color); border-radius: var(--radius-sm); font-family: inherit; font-size: 1rem; background: var(--bg-color); }
.form-control:focus { outline: none; border-color: var(--accent-color); box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.1); }
textarea.form-control { min-height: 150px; resize: vertical; }

/* FOOTER */
.site-footer { background: #0f172a; color: #94a3b8; padding: 4rem 0 2rem; margin-top: auto; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 3rem; margin-bottom: 3rem; }
.footer-title { color: white; font-size: 1.1rem; font-weight: 600; margin-bottom: 1.5rem; }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links li { margin-bottom: 0.75rem; }
.footer-links a:hover { color: white; }
.footer-bottom { border-top: 1px solid #1e293b; padding-top: 2rem; display: flex; justify-content: space-between; align-items: center; font-size: 0.9rem; }

/* RESPONSIVE */
@media (max-width: 768px) {
    .main-nav { display: none; position: absolute; top: 72px; left: 0; right: 0; background: var(--surface-color); flex-direction: column; padding: 1.5rem; border-bottom: 1px solid var(--border-color); box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1); gap: 1rem; }
    .main-nav.is-open { display: flex; }
    .mobile-toggle { display: block; }
    .hero h1 { font-size: 2.5rem; }
    .grid-3, .grid-2, .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
    .article-title { font-size: 2rem; }
}