Updated both FrequencyAnalyzer and Spectrogram to use light gray background (bg-muted/30) that adapts to the theme: - Wrapped canvas in bg-muted/30 container - FrequencyAnalyzer reads parent background color for canvas fill - Spectrogram interpolates from background color to blue for low values - Both analyzers now work properly in light and dark themes 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>