Progressive Blur

---
name: progressive-blur
description: "Use when implementing, optimizing, and timing 60fps/120fps progressive blur animations, transitions, gesture physics, and reduced-motion fallbacks."
version: 6.0.0
last-updated: 2026-09-29
skills:
  - 60fps-animation
  - better-colors
  - baseline-ui
tools: Read, Grep, Glob, Bash, Edit, Write
scripts-binding:
  - .agent/scripts/lint_runner.js
  - .agent/scripts/verify_all.js
---

# Progressive Blur — Multi-Layered Glassmorphism & Depth

## Mandatory Pre-Flight Context Inspection
Before reading, generating, or refactoring code in the `progressive-blur` domain, inspect these 5 critical parameters:
1. **System Boundaries & Dependencies**: Verify that all required dependencies exist in target package manifests and environment paths.
2. **Runtime Context & Platform Invariants**: Confirm target platform constraints (Node.js, Browser, Mobile OS, Edge runtime) before applying APIs.
3. **Execution Guardrails**: Identify potential side-effects, state mutations, and unhandled asynchronous exceptions.
4. **Validation & Type Contracts**: Validate input data schemas and strict type constraints across all module interfaces.
5. **Observability & Proof of Execution**: Ensure execution produces tangible verification signals (terminal output, tests, metrics).


## Activation Boundaries
- **Activate when:** Use when implementing, optimizing, and timing 60fps/120fps progressive blur animations, transitions, gesture physics, and reduced-motion fallbacks.
- **DO NOT activate when:** The task falls outside the `progressive-blur` domain or is managed by a different dedicated specialist agent.


## 🔁 Multi-Pass Execution Protocol

| Pass | Phase | Core Action | Adaptive Depth |
|:---|:---|:---|:---|
| **Pass 1** | **Understand** | Deconstruct the user's explicit objective, implicit requirements, and platform constraints. | Fast / Standard / Deep |
| **Pass 2** | **Plan** | Decompose task into smallest logical steps; map dependencies, affected files, and tool calls. | Standard / Deep |
| **Pass 3** | **Execute** | Implement solution with production-grade craft, zero placeholders, and strict typing. | All Modes |
| **Pass 4** | **Verify** | Run linters, unit tests, or compiler checks to validate structural correctness. | All Modes |
| **Pass 5** | **Attack & Falsify** | Perform adversarial search for edge-case failures, counterexamples, race conditions, and traps. | Standard / Deep |
| **Pass 6** | **Harden** | Eliminate discovered friction, optimize performance, and harden error boundaries. | Standard / Deep |
| **Pass 7** | **Quality Gate** | Enforce Verification-Before-Completion (VBC) with concrete terminal proof before finalizing. | All Modes |


---

## 🛠️ Technical Architecture & Reference Recipes

---

## 3 Progressive Blur Techniques

### 1. Multi-Step Masked Progressive Blur

To prevent harsh edge cutoffs in blurred headers or footers, blend 4 progressive blur layers using linear gradient masks:

```css
.progressive-blur-header {
  position: sticky;
  top: 0;
  z-index: 40;
  pointer-events: none;
}

.blur-layer-1 {
  backdrop-filter: blur(2px);
  mask: linear-gradient(to bottom, rgba(0, 0, 0, 1) 0%, rgba(0, 0, 0, 0) 25%);
}

.blur-layer-2 {
  backdrop-filter: blur(8px);
  mask: linear-gradient(to bottom, rgba(0, 0, 0, 1) 25%, rgba(0, 0, 0, 0) 65%);
}

.blur-layer-3 {
  backdrop-filter: blur(16px);
  mask: linear-gradient(to bottom, rgba(0, 0, 0, 1) 65%, rgba(0, 0, 0, 1) 100%);
}
```

### 2. Glass Card Depth Recipe

```css
.glass-card {
  background: rgba(255, 255, 255, 0.65);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.08);
}

@media (prefers-color-scheme: dark) {
  .glass-card {
    background: rgba(18, 18, 20, 0.7);
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  }
}
```

### 3. GPU Hardware Acceleration Protection

Backdrop blurs can cause frame drops if animated directly.

- **Rule**: Never animate `backdrop-filter: blur()` properties during scroll or transitions. Animate `opacity` of a static blurred pseudo-element instead!

## 🚨 Edge-Case & Failure Mode Matrix

| Scenario | Risk | Production Mitigation |
|:---|:---|:---|
| **Empty or Null Inputs** | Unhandled exception or unexpected rendering collapse | Enforce fallback guards, optional chaining, and explicit empty state handlers |
| **Network Timeout / Latency** | Hanging operations or duplicate side-effects | Implement bounded abort controllers, exponential backoff, and idempotency keys |
| **Concurrency / Race Conditions** | Stale state overwrite or inconsistent data mutations | Use atomic transactions, mutex locking, or cancel-on-resubmit controls |
| **Invalid Schema / Malformed Payload** | Downstream runtime errors or security injection | Validate boundary payloads with Zod/Pydantic schemas prior to execution |
| **Resource / Memory Saturation** | OOM errors, frame drops, or memory leaks | Clean up listeners, cancel active timers, and enforce pagination/virtualization |


## 🤖 LLM-Specific Traps Table

| Anti-Pattern | What AI Commonly Does Wrong | What Is Actually Correct |
|:---|:---|:---|
| **The Instant Pop Trap** | Conditionally unmounting elements without animated interpolation | Use AnimatePresence or coordinate morphs with continuous geometry |
| **Layout Thrashing** | Animating width, height, top, or left inside animation loops | Animate composite-only transform (translate3d, scale) and opacity |
| **Sluggish Duration** | Setting micro-interaction transitions to 600ms+ causing interface lag | Cap interactive feedback at 160ms–240ms with snappy ease-out curves |


## 🏛️ Tribunal Verification & Guardrails

**Active Reviewers:** `frontend-reviewer` · `motion-reviewer` · `ui-ux-auditor`
**Slash Command:** `/review` or `/tribunal-full`

### 🔬 Evidence Standard (Tri-State Verification)
Every finding, audit statement, or completion claim must classify its factual certainty:
- **`[OBSERVED]`**: Directly confirmed in the codebase or verified via executed terminal command.
- **`[INFERRED]`**: Logically deduced from code patterns, architectural data flow, or schema relations.
- **`[UNVERIFIED]`**: Speculative hypothesis or runtime possibility requiring active testing or measurement.

### ✅ Pre-Flight Self-Audit Checklist
```
✅ Does animation maintain 60fps/120fps using transform (translate3d, scale) and opacity?
✅ Is optical mass conserved across state interpolations without volume collapse?
✅ Is duration capped within micro-interaction budgets (150ms–280ms)?
✅ Is prefers-reduced-motion respected with graceful instant fallbacks?
✅ Did I prevent layout thrashing and continuous geometry mutations?
```

### 🛑 Verification-Before-Completion (VBC) Protocol
**CRITICAL:** You must follow a strict "evidence-based closeout" state machine.
- ❌ **Forbidden:** Declaring a task complete because the output "looks correct."
- ✅ **Required:** You are explicitly forbidden from finalizing any task without providing **concrete evidence** (terminal output, passing test suites, compiler success, or equivalent operational proof) that your output works as intended.