How can I help my younger brother develop empathy and healthy attitudes, insha'Allah?

Assalamu alaykum - I’m worried about my 15-year-old brother and could use some advice. He’s in a private all-boys school, plays on a boys’ football team, is in cadets, and attends the boys’ section at the masjid. He doesn’t have any female friends and really no regular chances to meet women in a respectful, supervised way. I keep hearing that letting boys have platonic interactions with girls helps them grow, but in our family and community we prefer gender segregation and we follow Islamic guidelines. He spends a lot of time on social media and gaming. A lot of what he reposts seems to glorify violence, macho attitudes, and other stuff that worries me. He won’t take me or our mother seriously, and he seems to have very little empathy - I tried to explain why a violent incident was wrong for 10–15 minutes, and he only understood it when someone else said the same thing later. We do take him hiking, fishing, to the gym - we try to keep him active - but I’m still scared for his future. I’m thinking of arranging some supervised community service with refugees or homeless people so he can meet and help those in need and maybe watch more documentaries about their lives. I want him to develop compassion and healthier attitudes while staying within our Islamic values. Has anyone guided a teen brother toward more empathy and balanced views without compromising our religious and cultural boundaries? What worked for you - volunteering ideas that are family-appropriate, ways to get him to listen to family, or gentle approaches to limit harmful online content? Any duas or small habits that helped shift a teen’s mindset would be really appreciated. JazakAllahu khayr.