This page reads your cart from localStorage, then loads course details from catalog.json. Quantity changes update totals instantly.
Storage keys:
rg_cart_v1: {"items":[{"id":"course-id","qty":1}],"coupon":{"code":"...","type":"percent|fixed","value":10}}
Estimator uses each course’s duration (in hours, if available) multiplied by quantity, then divides by your selected weekly hours to calculate weeks.