:root {
    --sidebar-w: 260px;
    --bg: #f8f9fb;
    --surface: #ffffff;
    --text: #1a1d26;
    --muted: #5c6370;
    --border: #e3e6ec;
    --accent: #7367f0;
    --accent-soft: #eeecff;
    --code-bg: #f1f3f8;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 15px;
    line-height: 1.65;
    color: var(--text);
    background: var(--bg);
}

.layout {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-w);
    flex-shrink: 0;
    background: var(--surface);
    border-right: 1px solid var(--border);
    padding: 1.25rem 0;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-brand {
    padding: 0 1.25rem 1rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 0.75rem;
}

.sidebar-brand h1 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--accent);
}

.sidebar-brand p {
    margin: 0.25rem 0 0;
    font-size: 0.78rem;
    color: var(--muted);
}

.sidebar nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.sidebar nav a {
    display: block;
    padding: 0.45rem 1.25rem;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.sidebar nav a:hover {
    background: var(--accent-soft);
    color: var(--accent);
}

.sidebar nav a.active {
    background: var(--accent-soft);
    color: var(--accent);
    border-left-color: var(--accent);
    font-weight: 600;
}

.content {
    flex: 1;
    min-width: 0;
    padding: 2rem 2.5rem 3rem;
    max-width: 920px;
}

.content h1 {
    margin: 0 0 1rem;
    font-size: 1.85rem;
    line-height: 1.25;
}

.content h2 {
    margin: 2rem 0 0.75rem;
    font-size: 1.25rem;
    padding-bottom: 0.35rem;
    border-bottom: 1px solid var(--border);
}

.content h3 {
    margin: 1.5rem 0 0.5rem;
    font-size: 1.05rem;
}

.content p {
    margin: 0 0 1rem;
}

.content ul,
.content ol {
    margin: 0 0 1rem;
    padding-left: 1.4rem;
}

.content li {
    margin-bottom: 0.35rem;
}

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

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

.content code {
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: 0.88em;
    background: var(--code-bg);
    padding: 0.12em 0.35em;
    border-radius: 4px;
}

.content pre {
    background: #1e2230;
    color: #e8eaef;
    padding: 1rem 1.15rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 0 0 1rem;
    font-size: 0.86rem;
    line-height: 1.5;
}

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

.content table {
    width: 100%;
    border-collapse: collapse;
    margin: 0 0 1.25rem;
    font-size: 0.92rem;
    background: var(--surface);
    box-shadow: var(--shadow);
    border-radius: 8px;
    overflow: hidden;
}

.content th,
.content td {
    border: 1px solid var(--border);
    padding: 0.55rem 0.75rem;
    text-align: left;
    vertical-align: top;
}

.content th {
    background: #f3f4f8;
    font-weight: 600;
}

.content strong {
    font-weight: 600;
}

.content em {
    font-style: italic;
}

.footer-note {
    margin-top: 2.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
    color: var(--muted);
}

@media (max-width: 768px) {
    .layout {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }

    .content {
        padding: 1.25rem 1rem 2rem;
    }
}

@media print {
    .sidebar {
        display: none;
    }

    .content {
        max-width: none;
        padding: 0;
    }
}