健身工作室工作台

Build a single-page fitness studio workbench as one self-contained HTML file with inline CSS (no build step, no external requests). Layout: fixed 200px left sidebar with brand, five nav items (Sessions, Members, PT Schedule, Renewals, Assessments) and a user chip; top bar with page title, search input and avatar; main area with a 4-card KPI row (Active members 412, Sessions today 14, Visits this week 986, Renewal rate 68%), a today timeline (6 session blocks with trainer, room, occupancy bar), a renewal risk table (5 rows: member, card type, days left, LTV badge), and a trainer availability grid for the week. Light neutral surface, 1px borders, rounded-2xl cards, system font, indigo #4f46e5 as the only accent. All data hardcoded mock data. Width 1208px.