This study will develop and evaluate a mobile-based co-design intervention (CesiKids) to enhance psychosocial resilience in hospitalized adolescents aged 12-18 diagnosed with cancer. The program will be created using Bronfenbrenner's Ecological Systems Theory and designed in collaboration with nurses, recovered adolescents, and parents. A randomized controlled design will be used. The intervention group will participate in a four-week structured program, while the control group will receive standard care. Psychosocial resilience and coping outcomes will be assessed at baseline, post-intervention, and follow-up. This research aims to offer an evidence-based, scalable model to support resilience among adolescents with cancer in clinical settings.