Young adult post-workout on a yoga mat in a modern gym studio, taking a front-camera selfie (matte black case, slight). Waist-up, casual off-center framing with crossed legs partly visible. Accomplished, slightly breathless smile toward phone. Dark-brown messy high ponytail with flyaways + damp temple strands; minimal makeup, dewy flush; preserve original face. Outfit: charcoal-gray medium-support sports bra with subtle sweat marks + wrinkles; black high-waisted compression leggings with faint lint + knee creases. No jewelry; black fitness tracker + extra hair tie on wrist; black hair tie in hair. Small towel bunched in one hand; matte stainless insulated bottle with stickers, condensation, cap loosened mid-sip near knee/shin. Background: light-gray walls, mat corners curled, two dumbbells aside, blurred squat rack + cable machine, faint mirror reflection, no others. Bright even overhead gym lighting; crisp realistic detail, slight skin shine; energetic post-workout vibe. --ar 9:16