animated positioned toke too much space - flutter

animated positioned took too much space while changing the position. the question is there is any way to minimize this space ? it ascends to safeare

the source code is below so you can try it:

class Test extends StatefulWidget {
  const Test({Key? key}) : super(key: key);

  @override
  State<Test> createState() => _TestState();
}

class _TestState extends State<Test> with TickerProviderStateMixin {
  bool selected = false;

  late AnimationController colorController;
  late Animation animation;

  @override
  initState() {
    super.initState();
    WidgetsBinding.instance!.addPostFrameCallback((_) {
      setState(() {
        selected = true;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    changeStatusColor(colorPrimary);
    return Scaffold(
      backgroundColor: colorPrimary,
      body: Stack(
        alignment: Alignment.bottomCenter,
        children: [
          AnimatedPositioned(
            curve: Curves.elasticOut,
            duration: Duration(milliseconds: 10000),
            width: MediaQuery.of(context).size.width,
            height: selected
                ? MediaQuery.of(context).size.height
                : MediaQuery.of(context).size.height * .7,
            top: selected
                ? 50.0
                : MediaQuery.of(context).size.height -
                    MediaQuery.of(context).size.height * .7,
            child: Container(
                padding: EdgeInsets.fromLTRB(26, 0, 26, 25.51),
                decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.vertical(top: Radius.circular(40)),
                ),
                child: Column(children: [])),
          ),
        ],
      ),
    );
  }
}