# Theme Detection Fix - v0.13.1

## Issue Addressed

The `optimize_display()` function in previous versions used hardcoded theme detection that defaulted to 'light' theme regardless of the actual environment theme. This affected display quality in dark-themed notebooks.

## Changes Made

**Fixed theme detection in `edaflow/display.py`:**

- Modified `_detect_colab_theme()` function to check environment variables (`COLAB_THEME`) when available
- Added fallback to 'auto' theme instead of hardcoded 'light' 
- Enhanced CSS to use media queries for dynamic theme adaptation
- Improved platform-specific theme detection

## Technical Details

**Before:**
```python
def _detect_colab_theme() -> str:
    # ... 
    return 'auto'  # Always returned 'auto', but CSS was still light-themed
```

**After:**
```python
def _detect_colab_theme() -> str:
    # Check environment variables first
    theme_hint = os.environ.get('COLAB_THEME', '').lower()
    if theme_hint in ['dark', 'light']:
        return theme_hint
    
    # Additional detection methods...
    return 'auto'  # Now with proper CSS support for auto-detection
```

**CSS improvements:**
- Added `@media (prefers-color-scheme: dark/light)` support
- Platform-specific selectors for Colab dark theme detection
- CSS variables for dynamic theme adaptation

## Impact

- Google Colab users should see improved theme compatibility
- Other notebook environments benefit from better auto-detection
- No breaking changes to existing API

## Testing

The fix has been validated with environment variable testing and platform detection. Users can verify theme detection behavior using the included test script.

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*This fix addresses user feedback regarding theme detection reliability in notebook environments.*
