Change - " main.dart " -

Let's start from the begining of the component by changing the - "main.dart" - as like as code given below.

We need to initialize three variable of data type double , color ,color which is used to change the state of the app and hover color changing , you can give any color for your taste.
Make a AnimatedContainer which is used as the main text container that required some animation,

After completing the container we move for the Layout Builder which return the current state of the app which help us to know the size of the page that is used to make the navbar collapse or expand , i directly change the size of the collapse height to make the magic happen.

Create the NavBar Button style:

Make a container that return a Icon of your own preffered icon and size , then we need to warp the container with inkwell() to detect the on Tap event , we also need to have a splash color to visible which will affect if dont use the material() Widget over the Inkwell (make color to trasnsparent in material widget) .

Create the NavBar item style:

Make a container that return a column of Text() which is returned from the list that created and size it , then we need to warp the container with inkwell() to detect the on Tap event , we also need to have a splash color to visible which will affect if dont use the material() Widget over the Inkwell (make color to trasnsparent in material widget).and also need a hover effect which inkwell dont have so we wrap them with the MouseRegion() widget which have lot more events in it we need to use the OnEnter and OnExit function to change the color of the container

Now you have a Nav Bar with some Responsiveness in it.Have a Good Day.... :) Buddy.

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