How can my parent Container hide the corners of the child Container

Question

The parent container has border radius, which I would like to apply also to its children. Instead, I get this

As you can see, the corners of the child container are above the border. How can I hide the corners of the child?

Container(
            width: screenWidth / 3,
            height: screenHeight * 0.8,
            decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(55),
                border: Border.all(
                  color: Colors.black26,
                ),
              ),
            child: Column(
              children: [
                Container(
                  width: screenWidth / 3,
                  height: 139,
                  color: Colors.amberAccent,
                )
              ],
            ),
          ),

Answer 1

you have to use ClipRRect widget.

Container(
           width: screenWidth / 3,
           height:screenHeight * 0.8,
           decoration: BoxDecoration(
               borderRadius: BorderRadius.circular(55),
               border: Border.all(
                 color: Colors.black26,
               ),
             ),
           child: ClipRRect(
             borderRadius: BorderRadius.circular(55),     
             child: Column(
               children: [
                 Container(
                   width: screenWidth / 3,
                   height: 139,
                   color: Colors.amberAccent,
                 )
               ],
             ),
           ),
         )