## ?? App Features

### ?? Core Features
- **Life Countdown**: Calculates elapsed and remaining time
- **Dual Mode Switch**: Death Countdown Mode vs. Life Countdown Mode
- **Custom Events**: Add birthdays, anniversaries, and custom important dates
- **Holiday Countdown**: Built-in countdown for important holidays
- **Desktop Widget**: Displays life progress on the home screen

### ?? Interface Features
- **Immersive Status Bar**: Automatically adapts to dark and light themes
- **Smooth Animations**: Beautiful animations for page transitions and button clicks
- **Dual Theme Design**:
- Death Mode: Dark theme emphasizes the preciousness of life
- Life Mode: Light theme showcases the beauty of life
- **Card Flip Effect**: 3D flip animation when switching modes

### ?? Data Display
- **Detailed Statistics**: Heart rate, respiration rate, blink rate
- **Percentage Display**: Percentage of elapsed and remaining time
- **Real-time Update**: Countdown automatically updates every minute
- **Zero-padded format**: All numbers are displayed as two digits (e.g., 05 instead of 5).

## ?? User Guide

### First Time Use
1. After launching the app, a welcome dialog will pop up.
2. Click the "Set Birthday" button and select your birthdate.
3. Set your life expectancy (default is 80).
4. Click "Start Trial" to enter the main interface.

### Main Interface Operations
- **Mode Switch**: Click the toggle button at the top to switch between Death Mode and Life Mode.
- **Statistics**: Each mode displays detailed statistics.
- **Settings**: Click the Settings button to modify your birthday and life expectancy.

### Custom Events
1. Click the "Custom Countdown" button on the main interface.
2. Click the "Add Event" button.
3. Enter the event information:
- Event Name
- Event Type (Birthday/Anniversary/Custom)
- Event Notes (optional)
- Select a date.
4. After saving, the event will appear in the list and a real-time countdown will begin.

### Holiday Countdown
1. Click the "Holiday Countdown" button on the main interface.
2. View the built-in countdown for important holidays.
3. Includes Spring Festival, Christmas, New Year's Day, and other holidays.

## 💯️ Technical Features

### Development Technology
- **Language**: Pure Java development, no third-party framework dependencies
- **Minimum support**: Android 6.0 (API 24)
- **Target version**: Android 14 (API 35)
- **UI components**: RecyclerView, CardView, custom View

### Data Storage
- **SharedPreferences**: Local storage of user settings and event data
- **Gson Serialization**: JSON serialization and storage of complex objects
- **Auto-Sync**: Data is persisted in real time, ensuring data is retained across app restarts

### Performance Optimization
- **Memory Management**: Automatically cleans up resources when the Activity is destroyed
- **Timer Optimization**: Updates only visible countdown components
- **Smooth Animation**: Hardware acceleration ensures 60fps animation

## 💯️ Interface Preview

### Main Interface
- Dual-Mode Card Design
- Real-Time Countdown Display
- Detailed Statistics
- Immersive Status Bar

### Custom Events
- Event List Display
- Real-Time Countdown Updates
- Add/Edit/Delete Functions
- Beautiful Type Selection Pop-up

### Settings Interface
- Birthday Date Picker
- Life Expectancy Settings
- About Page Information

## ?? Installation Instructions

### System Requirements
- Android 6.0 or higher
- At least 50MB of available storage space
- 2GB or more RAM recommended

### Installation Steps
1. Download the APK file
2. Allow installation of apps from unknown sources
3. Click Install
4. Launch the app and follow the setup wizard

## ?? Feature List

### ✅ Implemented Features
- [x] Life Countdown Calculator
- [x] Dual Mode Switching (Death/Life)
- [x] Customizable event management
- [x] Holiday countdown
- [x] Local data storage
- [x] Real-time countdown updates
- [x] Desktop widget
- [x] Immersive status bar
- [x] Beautiful animation effects