/* Reset and base */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --bg-dark: #0d1117;
    --bg-card: #161b22;
    --bg-hover: #21262d;
    --border: #30363d;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;
    --accent: #58a6ff;
    --accent-secondary: #3fb950;
    --accent-warning: #d29922;
    --accent-purple: #a371f7;
    --sidebar-width: 280px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-card);
    border-right: 1px solid var(--border);
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    padding: 1.5rem 0;
}

.sidebar-header {
    padding: 0 1.5rem 1.5rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1rem;
}

.sidebar-header h1 {
    font-size: 1.1rem;
    color: var(--accent);
    line-height: 1.3;
}

.nav-sections {
    list-style: none;
}

.nav-sections > li {
    margin-bottom: 0.25rem;
}

.nav-sections > li > a {
    display: block;
    padding: 0.5rem 1.5rem;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: background 0.15s;
}

.nav-sections > li > a:hover,
.nav-sections > li > a.active {
    background: var(--bg-hover);
    color: var(--accent);
}

.nav-subsections {
    list-style: none;
    display: none;
    padding-left: 1rem;
}

.nav-subsections.expanded {
    display: block;
}

.nav-sections > li:hover .nav-subsections {
    display: block;
}

.nav-subsections a {
    display: block;
    padding: 0.35rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.15s;
}

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

/* Main content */
.content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 2rem 3rem;
    max-width: 1000px;
}

.page-header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.page-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.page-header .subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.breadcrumb {
    margin-bottom: 1rem;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--text-secondary);
    text-decoration: none;
}

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

/* Intro section */
.intro {
    margin-bottom: 2.5rem;
}

.intro p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 1.05rem;
}

/* Section grid */
.section-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
    margin-bottom: 3rem;
}

.section-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    text-decoration: none;
    transition: border-color 0.2s, transform 0.2s;
}

.section-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.section-card.highlight {
    border-color: var(--accent-secondary);
}

.section-card .card-icon {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
}

.section-card h2 {
    color: var(--text-primary);
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
}

.section-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

/* Cross-cutting tradeoffs */
.cross-cutting {
    margin-bottom: 3rem;
}

.cross-cutting h2 {
    margin-bottom: 0.75rem;
}

.cross-cutting > p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.tradeoff-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem;
}

.tradeoff {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.25rem;
}

.tradeoff h3 {
    color: var(--accent-warning);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.tradeoff p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

.tradeoff a {
    color: var(--accent);
    text-decoration: none;
}

.tradeoff a:hover {
    text-decoration: underline;
}

/* FAQ grid */
.quick-answers h2 {
    margin-bottom: 1rem;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.faq-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.25rem;
    text-decoration: none;
    transition: border-color 0.2s;
}

.faq-card:hover {
    border-color: var(--accent);
}

.faq-card h3 {
    color: var(--text-primary);
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.faq-card p {
    color: var(--accent);
    font-size: 0.85rem;
    margin: 0;
}

/* Content pages */
h2 {
    color: var(--text-primary);
    font-size: 1.4rem;
    margin: 2rem 0 1rem 0;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border);
}

h3 {
    color: var(--text-primary);
    font-size: 1.15rem;
    margin: 1.5rem 0 0.75rem 0;
}

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

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

/* Callout boxes */
.callout {
    background: var(--bg-card);
    border-left: 4px solid var(--accent);
    border-radius: 0 8px 8px 0;
    padding: 1rem 1.25rem;
    margin: 1.5rem 0;
}

.callout.warning {
    border-left-color: var(--accent-warning);
}

.callout.success {
    border-left-color: var(--accent-secondary);
}

.callout h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.callout p {
    margin: 0;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.9rem;
}

th, td {
    padding: 0.75rem 1rem;
    text-align: left;
    border: 1px solid var(--border);
}

th {
    background: var(--bg-card);
    color: var(--accent);
    font-weight: 600;
}

td {
    background: var(--bg-dark);
    color: var(--text-secondary);
}

tr:hover td {
    background: var(--bg-card);
}

/* Code */
code {
    background: var(--bg-card);
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
    color: var(--accent-purple);
}

pre {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    overflow-x: auto;
    margin: 1rem 0;
}

pre code {
    background: none;
    padding: 0;
}

/* Diagram boxes */
.diagram {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    font-family: monospace;
    font-size: 0.85rem;
    white-space: pre;
    overflow-x: auto;
    text-align: center;
    color: var(--accent-secondary);
}

/* Comparison cards */
.comparison-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.comparison-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.25rem;
}

.comparison-card h4 {
    color: var(--accent);
    margin-bottom: 0.75rem;
}

.comparison-card ul {
    margin: 0;
    padding-left: 1.25rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.comparison-card li {
    margin-bottom: 0.35rem;
}

/* Key-value definitions */
.definition-list {
    margin: 1rem 0;
}

.definition-list dt {
    color: var(--accent);
    font-weight: 600;
    margin-top: 1rem;
}

.definition-list dd {
    color: var(--text-secondary);
    margin-left: 0;
    padding-left: 1rem;
    border-left: 2px solid var(--border);
}

/* Links section */
.related-links {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 1.25rem;
    margin-top: 2rem;
}

.related-links h3 {
    margin-top: 0;
    color: var(--text-primary);
}

.related-links ul {
    margin: 0;
    padding-left: 1.25rem;
}

.related-links li {
    margin-bottom: 0.35rem;
}

/* Page metadata */
.page-meta {
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
    color: var(--text-muted);
}

.page-meta .last-modified {
    margin-bottom: 1rem;
}

.page-changelog {
    margin-top: 1rem;
}

.page-changelog summary {
    cursor: pointer;
    color: var(--text-muted);
    font-weight: 500;
}

.page-changelog summary:hover {
    color: var(--text-secondary);
}

.page-changelog ul {
    margin-top: 0.5rem;
    padding-left: 1.5rem;
    font-size: 0.85rem;
}

.page-changelog li {
    margin-bottom: 0.25rem;
    color: var(--text-secondary);
}

.page-changelog .date {
    color: var(--text-muted);
    font-family: monospace;
}

/* Global changelog styles */
.changelog-entry {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.changelog-entry:last-child {
    border-bottom: none;
}

.changelog-entry h3 {
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.changelog-entry .version-date {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.changelog-entry ul {
    margin: 0;
    padding-left: 1.5rem;
}

.changelog-entry li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.changelog-tag {
    display: inline-block;
    padding: 0.1rem 0.4rem;
    border-radius: 3px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-right: 0.5rem;
}

.changelog-tag.new {
    background: var(--accent-secondary);
    color: var(--bg-dark);
}

.changelog-tag.updated {
    background: var(--accent);
    color: var(--bg-dark);
}

.changelog-tag.fixed {
    background: var(--accent-purple);
    color: #fff;
}

/* Responsive */
@media (max-width: 900px) {
    .sidebar {
        display: none;
    }
    .content {
        margin-left: 0;
        padding: 1.5rem;
    }
}