anchor.diff:    var chartVisibility = false;
     var factor = 0.0;
     List<double> normalizedPeaks = [];
  -  var padding = EdgeInsets.all(16.0);
  +  double padding = 16.0;
   
     static final _BackgroundState _backgroundState = _BackgroundState();
   
  
positive.code: 
    // focuses the darker portion with padding
    void focus(bool focus) {
      this.padding = focus ? EdgeInsets.all(0.0) : EdgeInsets.all(16.0);
      this.setStateIfMounted();
    }
  
  
negative.code:       constraints: BoxConstraints.expand(),
        color: Theme.of(context).accentColor,
        child: AnimatedPadding(
          padding: EdgeInsets.all(widget.padding),
          duration: Duration(milliseconds: 500),
          curve: Curves.easeInOutQuart,
          child: Column(
  