I am trying to add borders for each item in an expansion panel in Flutter.
I achieved the below by the code below.
The problem is that the border lines doesn’t cover entire width, but only till the up/down arrow.
I want the border to be full.
Can anyone please help me?

                        ExpansionPanel(
                          canTapOnHeader: true,
                          headerBuilder:
                              (BuildContext context, bool isExpanded) {
                            return Container(
                              margin: const EdgeInsets.symmetric(
                                  vertical:
                                      4.0), // Add vertical margin to separate panels
                              decoration: const BoxDecoration(
                                border: Border(
                                  top: BorderSide(
                                    color: Colors.grey, // Border color
                                    width: 1.0, // Border width
                                  ),
                                  bottom: BorderSide(
                                    color: Colors.transparent, // Border color
                                    width: 1.0, // Border width
                                  ),
                                ),
                              ),
                              child: ListTile(
                                  title: Text(
                                'Which city do you want to travel from?',
                                style: Theme.of(context)
                                    .textTheme
                                    .titleSmall!
                                    .copyWith(
                                      height: 1.5,
                                      color: const Color(0xFF171A1F),
                                    ),
                              )),
                            );
                          },
                          .....//the body code