# Responsive Section Navigation
Navigation pattern for multi-section pages (reviews, recaps, dashboards). Provides a sticky sidebar TOC on desktop and a sticky horizontal scrollable bar on mobile.
## Layout Structure
The page uses a two-column CSS Grid: sidebar (TOC) + main content. On mobile it collapses to single-column with the TOC becoming a horizontal bar.
```html
```
Key structural rules:
- `` is the **first child** of `.wrap`
- All page content goes inside ``
- Every section heading gets an `id="s1"`, `id="s2"`, etc.
- TOC links use `href="#s1"` matching those IDs
- Keep TOC link text short (truncate long section names)
## CSS
### Wrap (grid layout)
```css
.wrap {
max-width: 1400px;
margin: 0 auto;
display: grid;
grid-template-columns: 170px 1fr;
gap: 0 40px;
}
.main { min-width: 0; }
```
### TOC — Desktop (sticky sidebar)
```css
.toc {
position: sticky;
top: 24px;
align-self: start;
padding: 14px 0;
grid-row: 1 / -1;
max-height: calc(100dvh - 48px);
overflow-y: auto;
}
.toc::-webkit-scrollbar { width: 3px; }
.toc::-webkit-scrollbar-thumb { background: var(--surface-elevated); border-radius: 2px; }
.toc-title {
font-family: var(--font-mono);
font-size: 9px;
font-weight: 700;
text-transform: uppercase;
letter-spacing: 2px;
color: var(--text-dim);
padding: 0 0 10px;
margin-bottom: 8px;
border-bottom: 1px solid var(--border);
}
.toc a {
display: block;
font-size: 11px;
color: var(--text-dim);
text-decoration: none;
padding: 4px 8px;
border-radius: 5px;
border-left: 2px solid transparent;
transition: all 0.15s;
line-height: 1.4;
margin-bottom: 1px;
}
.toc a:hover { color: var(--text); background: var(--surface2); }
.toc a.active { color: var(--text); border-left-color: var(--accent); }
```
Replace `var(--accent)` with your page's primary accent color variable (e.g., `var(--orange)`, `var(--blue)`).
### TOC — Mobile (sticky horizontal bar)
```css
@media (max-width: 1000px) {
.wrap { grid-template-columns: 1fr; padding-top: 0; }
body { padding-top: 0; }
.toc {
position: sticky;
top: 0;
z-index: 200;
max-height: none;
display: flex;
gap: 4px;
align-items: center;
overflow-x: auto;
-webkit-overflow-scrolling: touch;
background: var(--bg);
border-bottom: 1px solid var(--border);
padding: 10px 0;
margin: 0 -40px;
padding-left: 40px;
padding-right: 40px;
grid-row: auto;
}
.toc::-webkit-scrollbar { display: none; }
.toc-title { display: none; }
.toc a {
white-space: nowrap;
flex-shrink: 0;
border-left: none;
border-bottom: 2px solid transparent;
border-radius: 4px 4px 0 0;
padding: 6px 10px;
font-size: 10px;
}
.toc a.active {
border-left: none;
border-bottom-color: var(--accent);
background: var(--surface);
}
.main { padding-top: 20px; }
/* Offset scroll target so headings clear the sticky bar */
.sec-head { scroll-margin-top: 52px; }
}
```
Adjust `margin: 0 -40px` and `padding-left/right: 40px` to match your `body` padding so the bar bleeds edge-to-edge.
## JavaScript — Scroll Spy
Place before `
`, after any Mermaid init:
```html