update README

README.md

@@ -76,13 +76,34 @@ npm run build
 
 ## How It Works
 
-1. **Geolocation**: User grants location permissions
+1. **Location Input**: User can either:
+   - Grant browser geolocation permissions (automatic location detection)
+   - Manually enter latitude/longitude coordinates
 2. **Data Fetch**: Current weather and air quality data retrieved from Open-Meteo API
 3. **Weather Comfort Scoring**: Algorithm calculates comfort based on temperature, humidity, cloud cover, wind, and precipitation
 4. **Progression Selection**: Chooses appropriate chord progression based on weather mood
 5. **Audio Generation**: All instruments and effects dynamically adjust to conditions
 6. **Real-time Updates**: Audio parameters smoothly transition as weather changes
 
+## Geolocation & Browser Compatibility
+
+The app supports two methods for location input:
+
+**Automatic Geolocation:**
+- Requires HTTPS in production (localhost works without HTTPS)
+- User must grant browser permission when prompted
+- May not work on some mobile browsers or restrictive browser settings
+
+**Manual Coordinate Entry:**
+- Fallback option for when geolocation is unavailable
+- Accepts latitude (-90 to 90) and longitude (-180 to 180)
+- Works on all devices and browsers
+- Useful for exploring weather from different locations
+
+**Production Requirements:**
+- Must be served over HTTPS for geolocation to work
+- Development server uses `@vitejs/plugin-basic-ssl` for local HTTPS
+
 ## Project Structure
 
 ```