anchor.diff:                gradient: new LinearGradient(
                   begin: const FractionalOffset(0.5, 0.0),
                   end: const FractionalOffset(0.5, 0.40),
  -                colors: <Color>[const Color(0x60000000), const Color(0x00000000)]
  +                colors: <Color>[const Color(0x60000000), const Color(0x00000000)],
                 )
               )
             )
           ),
         ),
  -      body: _buildContainer(context)
  +      body: _buildBody(context),
       );
     }
   
     // The full page content with the recipe's image behind it. This
     // adjusts based on the size of the screen. If the recipe sheet touches
     // the edge of the screen, use a slightly different layout.
  -  Widget _buildContainer(BuildContext context) {
  +  Widget _buildBody(BuildContext context) {
  +    debugPaintSizeEnabled = false;
  +    debugPaintPointersEnabled = true;
       final bool isFavorite = _favoriteRecipes.contains(config.recipe);
       final Size screenSize = MediaQuery.of(context).size;
       final bool fullWidth = (screenSize.width < _kRecipePageMaxWidth);
       final double appBarHeight = _getAppBarHeight(context);
  -    const double fabHalfSize = 28.0;  // TODO(mpcomplete): needs to adapt to screen size
       return new Stack(
         children: <Widget>[
           new Positioned(
             top: 0.0,
             left: 0.0,
             right: 0.0,
  -          height: appBarHeight + fabHalfSize,
  +          height: appBarHeight + _kFabHalfSize,
             child: new Hero(
               tag: config.recipe.imagePath,
               child: new Image.asset(
                 config.recipe.imagePath,
  -              fit: fullWidth ? ImageFit.fitWidth : ImageFit.cover
  -            )
  -          )
  +              fit: fullWidth ? ImageFit.fitWidth : ImageFit.cover,
  +            ),
  +          ),
           ),
           new ClampOverscrolls(
             edge: ScrollableEdge.both,
  
positive.code:     ],
      steps: const<RecipeStep>[
        const RecipeStep(duration: '3 min', description: 'Stir'),
        const RecipeStep(duration: '45 min', description: 'Cook')
      ]
    ),
  ];
  
negative.code:     ],
      steps: const<RecipeStep>[
        const RecipeStep(duration: '3 min', description: 'Stir'),
        const RecipeStep(duration: '45 min', description: 'Cook'),
      ],
    ),
    const Recipe(
      name: 'Bacon Sprouts',
  