Ledger

Build **Ledger** — a genuinely usable envelope-budgeting tool. Envelope budgeting is a simple, old idea: you take your income for the month and divide it into named envelopes (rent, groceries, transport, savings, fun…), and you only spend from what each envelope holds. Ledger should make that feel calm, honest, and even satisfying. It needs to actually work, with real state and real arithmetic: - The person sets a monthly income and creates/edits spending envelopes with target amounts. - The tool always shows what's allocated versus what's left to allocate, and never lets the numbers lie — over-allocating is shown clearly. - They can record spending against an envelope and watch its remaining balance fall; an envelope going negative is surfaced honestly, not hidden. - A clear at-a-glance overview of the whole month — where the money is, what's left, what's overspent. - Sensible starting content so it's not empty on first load, and the ability to reset. Persisting to localStorage is a nice touch if you want it, but everything can also live in memory. The register is calm, trustworthy, and precise — a tool that respects the user and their money, closer to a well-made native app than a flashy landing page. Build all UI yourself; no external images or network libraries. This challenge stresses **productivity-tool craft** — real interactive state, correct math, clear information design, and trustworthy UX. All design decisions — layout, palette, typography, interactions, features beyond the essentials — are yours. There is no single right answer; make something with a point of view.