• Screen: SCR-BIL.10 — Subscription Success
• Use case: UC-BIL.01 — Purchase Course (main flow step 5, post-checkout; screen owned by SUC-BIL-01, shared with UC-BIL.03)
• Sub-use case: SUC-BIL-01 — Checkout via BCEL (invoked by UC-BIL.01, UC-BIL.03)
• Current context: Main flow

Post-BCEL checkout success confirmation — shown after callback is verified and Subscription is activated. Displays a success banner + read-only purchase summary (item, amount, reference code, payment date, access type, access from, access until) + prominent "Start" CTA. On "Start", system checks Course.is_cohort (cross-subsystem LMS Core): standard course (is_cohort=false) → Lesson Player (SCR-PLY.01); cohort course (is_cohort=true) → Enrollment Confirmation (SCR-LMS.05). Page is reload-safe — loads Transaction state from ref_code; non-success statuses redirect back to the appropriate flow.

• item_name "Item" — text · lookup Transaction.product_id → Product.name · always · read-only
• amount "Amount" — number · Transaction.amount · always · read-only
• ref_code "Reference No." — text · Transaction.ref_code · always · read-only
• paid_at "Paid at" — datetime · Transaction.callback_received_at · always · read-only
• product_type "Access type" — enum [lifetime, monthly, yearly] · Product.type · always · read-only
• access_from "Access from" — date · Subscription.started_at · always · read-only
• access_until "Access until" — date · Subscription.expiry_date · visible when product_type != lifetime · read-only

• start "Start" — always enabled · triggers SUC-BIL-01-M-12 → routes into LMS Core: is_cohort=false → Lesson Player (SCR-PLY.01) (SUC-BIL-01-A-12A-1); is_cohort=true → Enrollment Confirmation (SCR-LMS.05) (SUC-BIL-01-M-13)

1. Support concurrent users per NFR-01 (100–200 peak) [refs: NFR-01]
2. Works on connection ≤1 Mbps — lightweight confirmation page (static, no polling/heavy assets); summary fields from preloaded Transaction record [refs: NFR-02]
3. TLS 1.2+ in transit; user sees only their own Transaction/Subscription (server-side session + ref_code ownership check) [refs: NFR-03, NFR-10]
4. Responsive — single-column layout; "Start" button full-width on mobile [refs: NFR-08]
5. WCAG — success message announced via aria-live="polite"; focus moves to heading on load; "Start" is keyboard-accessible primary CTA [refs: NFR-09]
6. "Start" is prominent primary CTA above the fold — one click to enter the course [refs: NFR-04]
7. On "Start": system checks Course.is_cohort (cross-subsystem LMS Core) — standard course (is_cohort=false) → Lesson Player (SCR-PLY.01); cohort course (is_cohort=true) → Enrollment Confirmation (SCR-LMS.05) [refs: —]
8. Reload-safe — Transaction state loaded from ref_code; non-success statuses redirect back to appropriate flow [refs: SS-BIL.02]