Your favorite pothos is bursting out of its pot and you need to know exactly what size pot to graduate it into — too big and the roots will rot, too small and it'll be cramped again in weeks.

Build a single-page widget where a user enters the **current pot diameter** (in inches or centimeters) and the app instantly displays:
- The **recommended next pot size** (typically 1–2 inches larger for most houseplants)
- A **visual comparison** showing the old pot vs the new pot as simple circles or rectangles drawn on the page
- A short tip blurb (e.g. 'Choose terracotta for moisture-loving roots!' or 'Go ceramic for slower drying soil') that changes based on the size range selected

The user can also pick a **plant category** from a short dropdown (succulents, tropical, leafy greens, orchids) which adjusts the sizing logic — succulents prefer only ½-inch bumps, orchids stay snug, tropicals like a full 2-inch jump.

All state lives in the page with no backend. The interaction is: type a number, pick a category, see the recommendation and visual update immediately.