Compare
Side-by-side code comparison. Each fenced code block becomes a labeled panel. Labels default to the code block's language.
Basic usage
Panels are automatically labeled by their code block language.
{% compare %}
```javascript
function greet(name) {
return `Hello, ${name}!`;
}
```
```typescript
function greet(name: string): string {
return `Hello, ${name}!`;
}
```
{% /compare %}<div data-rune="compare" data-rune-fields="{"layout":"side-by-side"}" data-code-host>
<div data-panels data-name="panels">
<div data-panel>
<span data-label>javascript</span>
<div class="rf-codeblock">
<pre data-language="javascript">
<code data-language="javascript">function greet(name) {
return `Hello, ${name}!`;
}
</code>
</pre>
</div>
</div>
<div data-panel>
<span data-label>typescript</span>
<div class="rf-codeblock">
<pre data-language="typescript">
<code data-language="typescript">function greet(name: string): string {
return `Hello, ${name}!`;
}
</code>
</pre>
</div>
</div>
</div>
</div>javascript
function greet(name) {
return `Hello, ${name}!`;
}
typescript
function greet(name: string): string {
return `Hello, ${name}!`;
}
<div class="rf-compare rf-compare--side-by-side" data-code-host data-layout="side-by-side" data-rune="compare" data-density="full">
<div data-panels data-name="panels" class="rf-compare__panels">
<div data-panel>
<span data-label>javascript</span>
<div class="rf-codeblock">
<pre data-language="javascript"><code data-language="javascript">function greet(name) {
return `Hello, ${name}!`;
}
</code></pre>
</div>
</div>
<div data-panel>
<span data-label>typescript</span>
<div class="rf-codeblock">
<pre data-language="typescript"><code data-language="typescript">function greet(name: string): string {
return `Hello, ${name}!`;
}
</code></pre>
</div>
</div>
</div>
</div>Custom labels
Use the labels attribute to override the default language-based labels.
{% compare labels="Before, After" %}
```javascript
const data = fetch('/api').then(r => r.json());
```
```javascript
const data = await fetch('/api').then(r => r.json());
```
{% /compare %}<div data-rune="compare" data-rune-fields="{"layout":"side-by-side"}" data-code-host>
<div data-panels data-name="panels">
<div data-panel>
<span data-label>Before</span>
<div class="rf-codeblock">
<pre data-language="javascript">
<code data-language="javascript">const data = fetch('/api').then(r => r.json());
</code>
</pre>
</div>
</div>
<div data-panel>
<span data-label>After</span>
<div class="rf-codeblock">
<pre data-language="javascript">
<code data-language="javascript">const data = await fetch('/api').then(r => r.json());
</code>
</pre>
</div>
</div>
</div>
</div>Before
const data = fetch('/api').then(r => r.json());
After
const data = await fetch('/api').then(r => r.json());
<div class="rf-compare rf-compare--side-by-side" data-code-host data-layout="side-by-side" data-rune="compare" data-density="full">
<div data-panels data-name="panels" class="rf-compare__panels">
<div data-panel>
<span data-label>Before</span>
<div class="rf-codeblock">
<pre data-language="javascript"><code data-language="javascript">const data = fetch('/api').then(r => r.json());
</code></pre>
</div>
</div>
<div data-panel>
<span data-label>After</span>
<div class="rf-codeblock">
<pre data-language="javascript"><code data-language="javascript">const data = await fetch('/api').then(r => r.json());
</code></pre>
</div>
</div>
</div>
</div>Attributes
| Attribute | Type | Required | Description |
|---|---|---|---|
layout | "side-by-side" | "stacked" | — | Display panels side-by-side or stacked |
labels | string | — | Comma-separated custom labels for each panel |
title | string | — | Optional title displayed above the panels |
Universal attributes
bg
The background layer (SPEC-088): image, video, gradient, flat overlay wash and legibility scrim, in a single injected layer behind the rune's content.
| Attribute | Type | Required | Description |
|---|---|---|---|
bg | string | — | Background preset applied to this block |
bg-from | string | — | Gradient start colour — a semantic token name (→ var(--rf-color-*)) |
bg-gradient | "to-t" | "to-b" | "to-l" | "to-r" | "to-tr" | "to-br" | "to-bl" | "to-tl" | — | Gradient direction (bounded named set) |
bg-gradient-type | "linear" | "radial" | "conic" | — | Gradient type |
bg-to | string | — | Gradient end colour — a semantic token name |
bg-via | string | — | Optional middle gradient stop — a semantic token name |
scrim | "top" | "bottom" | "left" | "right" | "none" | — | Scrim direction (heaviest edge); presence turns the scrim on, "none" opts out of the default cover scrim |
scrim-blur | "none" | "sm" | "md" | "lg" | — | Frost scrim blur amount |
scrim-strength | "sm" | "md" | "lg" | — | Gradient scrim strength |
scrim-tone | "dark" | "light" | — | Whether the scrim darkens (for light text) or lightens (for dark text) |
scrim-type | "gradient" | "frost" | — | Scrim treatment: gradient (default) or frost (backdrop blur) |
elevation
The chrome/depth ladder (SPEC-107). The skin maps each rung to a chrome bundle by attribute, so there is no BEM class.
| Attribute | Type | Required | Description |
|---|---|---|---|
elevation | "sunken" | "flush" | "flat" | "raised" | "floating" | "overlay" | "none" | "sm" | "md" | "lg" | — | Surface depth on the SPEC-107 ladder (sunken→overlay); none/sm/md/lg are deprecated aliases |
inset
Internal padding override.
| Attribute | Type | Required | Description |
|---|---|---|---|
inset | "flush" | "tight" | "default" | "loose" | "breathe" | — | Inner padding of this block |
motion
Scroll-reveal entrance (SPEC-105). The author declares the character, the theme owns the choreography, a behaviour owns the timing.
| Attribute | Type | Required | Description |
|---|---|---|---|
reveal | "none" | "fade" | "slide" | "scale" | "blur" | — | Scroll-reveal entrance character (none|fade|slide|scale|blur); the theme owns the choreography |
stagger | boolean | — | Cascade this block's items in as it reveals (no-op on single-child runes) |
spacing
Block-level rhythm override.
| Attribute | Type | Required | Description |
|---|---|---|---|
spacing | "flush" | "tight" | "default" | "loose" | "breathe" | — | Vertical spacing above and below this block |
substrate
Generated pattern fills (SPEC-087). Markers only — the engine sets the attributes and cell/opacity custom properties, CSS draws the pattern.
| Attribute | Type | Required | Description |
|---|---|---|---|
substrate | "dots" | "grid" | "lines" | "cross" | "checker" | "none" | — | Generated surface pattern |
substrate-fill | "inherit" | "inset" | — | Surface fill the pattern sits on (full colour stays with tint) |
substrate-opacity | "sm" | "md" | "lg" | — | Pattern ink strength |
substrate-size | "sm" | "md" | "lg" | — | Pattern cell size |
substrate-target | "self" | "media" | — | Which surface the pattern fills (overrides the rune/theme default) |
tint
Per-rune colour override (SPEC-053): a named tint from the theme registry, with inline per-token overrides layered on top.
| Attribute | Type | Required | Description |
|---|---|---|---|
tint | string | — | Color tint preset applied to this block |
tint-mode | "auto" | "dark" | "light" | — | Whether the tint adapts to auto, dark, or light mode |
width
The track a block rune occupies.
| Attribute | Type | Required | Description |
|---|---|---|---|
width | "compact" | "narrow" | "content" | "wide" | "full" | — | Maximum width constraint for this block |
| Not available | Why |
|---|---|
| dropcap, reading | this rune declares no prose body |
| frame | this rune declares neither a `frameTarget` nor a media section |
| prominence | this rune has no page-section header |