# [Feature Name] Design Document

## Overview

[High-level description of the feature architecture - describe the overall approach, key design decisions, and how it fits into the larger system]

## Architecture

[Description of architectural approach and patterns used]

### Component Hierarchy

```
[FeatureName]View (Root)
├── [HeaderComponent] (Navigation and context)
├── [MainContainer] (Primary content)
│   ├── [ContentSection1]
│   │   ├── [SubComponent1]
│   │   └── [SubComponent2]
│   ├── [ContentSection2]
│   │   └── [SubComponent3]
│   └── [ActionSection]
│       └── [ActionButtons]
├── [FloatingElements] (Overlays, FABs)
└── [ModalComponents] (Sheets, Dialogs)
```

## Components and Interfaces

### [MainComponent]
- **Purpose**: [What this component does and why]
- **Platform-Specific Design**:
  - iOS: [Apple HIG considerations, SF Symbols, native patterns]
  - Android: [Material Design 3 components, patterns]
- **Key Features**:
  - [Feature 1 with implementation detail]
  - [Feature 2 with implementation detail]
  - [Animations and transitions]

### [SubComponent1]
- **Purpose**: [Component purpose]
- **Visual Design**:
  - [Layout specifications]
  - [Color and typography]
  - [Spacing and sizing]
- **Interaction Design**:
  - [Touch/click behavior]
  - [Hover states (if applicable)]
  - [Animation specs]

## Data Models

### [PrimaryModel]
```swift
// iOS
struct [ModelName]: Codable, Identifiable {
    let id: UUID
    let property1: String
    let property2: Int
    let optionalProperty: String?
    let nestedObject: [NestedType]
    let createdAt: Date
    let updatedAt: Date
    
    enum CodingKeys: String, CodingKey {
        case id
        case property1 = "property_1"
        // ... mapping for API compatibility
    }
}
```

```kotlin
// Android
data class [ModelName](
    val id: String,
    val property1: String,
    val property2: Int,
    val optionalProperty: String?,
    val nestedObject: List<NestedType>,
    val createdAt: Instant,
    val updatedAt: Instant
)
```

### [StateModel]
```swift
// iOS - ViewModel State
enum [Feature]ViewState {
    case idle
    case loading
    case loaded([DataModel])
    case error(Error)
    case empty
}
```

```kotlin
// Android - UI State
sealed interface [Feature]UiState {
    data object Loading : [Feature]UiState
    data class Success(val data: List<DataModel>) : [Feature]UiState
    data class Error(val message: String) : [Feature]UiState
    data object Empty : [Feature]UiState
}
```

## Correctness Properties

*Properties serve as the bridge between requirements and verifiable correctness guarantees.*

**Property 1: [Property Name]**
*For any* [scenario/input], the system should [expected behavior across all conditions]
**Validates: Requirements 1.1, 1.2, 1.3**

**Property 2: [Property Name]**
*For any* [scenario/input], the system should [expected behavior]
**Validates: Requirements 2.1, 2.2**

**Property 3: Error Handling Correctness**
*For any* error condition, the system should [graceful handling, user feedback, recovery options]
**Validates: Requirements 3.1, 3.2, 3.3**

## UI/UX Design Specifications

### Visual Design System

**Colors:**
| Token | Light Mode | Dark Mode | Usage |
|-------|------------|-----------|-------|
| Primary | #[hex] | #[hex] | [usage] |
| Secondary | #[hex] | #[hex] | [usage] |
| Background | #[hex] | #[hex] | [usage] |

**Typography:**
| Style | Font | Size | Weight | Usage |
|-------|------|------|--------|-------|
| Title | [font] | 24pt | Bold | [usage] |
| Body | [font] | 16pt | Regular | [usage] |

**Spacing:**
| Token | Value | Usage |
|-------|-------|-------|
| xs | 4pt | [usage] |
| sm | 8pt | [usage] |
| md | 16pt | [usage] |

### Animation Specifications

| Animation | Duration | Easing | Description |
|-----------|----------|--------|-------------|
| Appear | 300ms | easeOut | [description] |
| Disappear | 200ms | easeIn | [description] |
| Spring | 0.5s/0.7 | spring | [response/damping] |

## Performance Considerations

- **Lazy Loading**: [What should be lazy loaded]
- **Caching Strategy**: [How data should be cached]
- **Memory Management**: [Memory considerations]

## Security Considerations

- **Data Encryption**: [What needs encryption]
- **Input Validation**: [Validation requirements]
- **Authentication**: [Auth requirements]