feat(registry): add blend-difference text effect component

docs/catalog/components/caption-blend-difference.mdx

@@ -0,0 +1,79 @@
+---
+title: "Blend Difference"
+description: "Auto-inverting captions using mix-blend-mode: difference — text flips between white and black per-pixel against the background"
+---
+
+# Blend Difference
+
+Auto-inverting captions using mix-blend-mode: difference — text flips between white and black per-pixel against the background
+
+`text` `effect` `blend-mode` `contrast` `inversion`
+
+## Install
+
+<CodeGroup>
+
+```bash Terminal
+npx hyperframes add caption-blend-difference
+```
+
+</CodeGroup>
+
+## How It Works
+
+White text with `mix-blend-mode: difference` inverts per-pixel against whatever is behind it:
+
+- **Dark background** → text stays white
+- **Light background** → text flips to black
+- **Color background** → text becomes the complement (blue → orange, red → cyan)
+
+The composition root needs `isolation: isolate` so the blend operates against sibling content (video, images) rather than the page background.
+
+## Variants
+
+| Class | Blend Mode | Effect |
+| --- | --- | --- |
+| `.blend-difference` | `difference` | Hard per-pixel inversion — maximum contrast |
+| `.blend-difference-soft` | `exclusion` | Softer inversion — less harsh on midtones |
+| `.blend-difference-screen` | `screen` | Text glows on dark areas, fades on light |
+
+## Example
+
+```html
+<div data-composition-id="root" style="isolation: isolate;">
+  <video src="video.mp4" muted playsinline
+         data-start="0" data-duration="30" data-track-index="0" />
+
+  <div class="clip blend-difference"
+       data-start="0" data-duration="5" data-track-index="1"
+       style="position: absolute; inset: 0; z-index: 10;
+              display: flex; align-items: center; justify-content: center;">
+    <span style="font-size: 120px; font-weight: 800;">
+      YOUR CAPTION
+    </span>
+  </div>
+</div>
+```
+
+## CSS Custom Properties
+
+| Property | Default | Description |
+| --- | --- | --- |
+| `--blend-caption-color` | `white` | Base text color before blending |
+| `--blend-mode` | `difference` | Override blend mode on `.blend-difference` |
+
+## Details
+
+| Property | Value |
+| --- | --- |
+| Type | Component |
+
+## Files
+
+| File | Target | Type |
+| --- | --- | --- |
+| `caption-blend-difference.html` | `compositions/components/caption-blend-difference.html` | hyperframes:snippet |
+
+## Usage
+
+Open `compositions/components/caption-blend-difference.html` and paste its contents into your composition. See the comment header in the file for detailed instructions.

docs/docs.json

@@ -197,6 +197,7 @@
           {
             "group": "Effects",
             "pages": [
+              "catalog/components/caption-blend-difference",
               "catalog/components/grain-overlay",
               "catalog/components/grid-pixelate-wipe",
               "catalog/components/shimmer-sweep",

registry/components/caption-blend-difference/caption-blend-difference.html

@@ -0,0 +1,83 @@
+<!--
+  Blend Difference — auto-inverting captions via mix-blend-mode.
+
+  Text color inverts per-pixel against whatever is behind it:
+  white stays white on dark areas, flips to black on light areas.
+  On color video, white inverts to the complement (blue → orange,
+  red → cyan, green → magenta).
+
+  Setup:
+  1. The composition root (or a shared ancestor of both the video
+     and the caption layer) MUST have `isolation: isolate` so the
+     blend operates against sibling content, not the page background.
+  2. Add class="blend-difference" to any caption container.
+  3. Set caption text color to white. The blend mode handles the rest.
+
+  Works on any element — divs, spans, SVG text, even images.
+
+  Customize:
+  - --blend-caption-color: base text color (default white)
+  - Change blend mode via --blend-mode to 'exclusion' for a softer effect
+
+  Variants:
+  - .blend-difference         → standard per-pixel inversion
+  - .blend-difference-soft    → exclusion mode, less harsh contrast
+  - .blend-difference-screen  → text glows on dark, fades on light
+-->
+
+<style>
+  .blend-difference {
+    mix-blend-mode: var(--blend-mode, difference);
+    color: var(--blend-caption-color, white);
+    pointer-events: none;
+  }
+
+  .blend-difference-soft {
+    mix-blend-mode: exclusion;
+    color: var(--blend-caption-color, white);
+    pointer-events: none;
+  }
+
+  .blend-difference-screen {
+    mix-blend-mode: screen;
+    color: var(--blend-caption-color, white);
+    pointer-events: none;
+  }
+</style>
+
+<!--
+  Composition setup example:
+
+  <div data-composition-id="root" ... style="isolation: isolate;">
+
+    <video id="bg" data-start="0" data-duration="30" data-track-index="0"
+           src="video.mp4" muted playsinline></video>
+
+    <div class="clip blend-difference" data-start="0" data-duration="5" data-track-index="1"
+         style="position: absolute; inset: 0; z-index: 10;
+                display: flex; align-items: center; justify-content: center;">
+      <span style="font-size: 120px; font-weight: 800; text-transform: uppercase;">
+        YOUR CAPTION
+      </span>
+    </div>
+  </div>
+
+
+  Timeline integration — animate captions normally, blend mode is passive:
+
+  tl.from(".caption", {
+    y: 50, opacity: 0, duration: 0.6, ease: "expo.out"
+  }, 0.2);
+
+
+  Notes:
+  - isolation: isolate on the composition root is REQUIRED.
+    Without it, blend mode composes against the page background
+    (usually white or black) and you get no inversion.
+  - Works with any GSAP animation — the blend composites every frame.
+  - For caption containers with multiple text elements, apply the
+    class to the shared parent, not each text element individually.
+  - On pure black backgrounds, white text stays white (difference
+    of white and black = white). The effect is most visible when
+    the background has varied luminance or color.
+-->

registry/components/caption-blend-difference/registry-item.json

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+{
+  "$schema": "https://hyperframes.heygen.com/schema/registry-item.json",
+  "name": "caption-blend-difference",
+  "type": "hyperframes:component",
+  "title": "Blend Difference",
+  "description": "Auto-inverting text using mix-blend-mode: difference — flips between white and black per-pixel against the background",
+  "tags": ["text", "effect", "blend-mode", "contrast", "inversion"],
+  "files": [
+    {
+      "path": "caption-blend-difference.html",
+      "target": "compositions/components/caption-blend-difference.html",
+      "type": "hyperframes:snippet"
+    }
+  ]
+}

registry/registry.json

@@ -127,6 +127,10 @@
       "name": "caption-highlight",
       "type": "hyperframes:component"
     },
+    {
+      "name": "caption-blend-difference",
+      "type": "hyperframes:component"
+    },
     {
       "name": "instagram-follow",
       "type": "hyperframes:block"