Almanac-Converter

A smart-bar unit converter, live-currency tool, and unit-aware calculator — one input that understands conversions, expressions, and plain arithmetic. Ships as a statically prerendered, installable PWA with no backend.

Features

• Smart bar — 12 km to mi, 5 ft 10 in to cm, 2 lakh inr to usd, 15% of 240, 1250 * 1.08, sqrt(16). Live results as you type, with a swap button (⇄) to flip direction and unit autocomplete after to.
• Compound-unit math — 100 km / 2 h to mph, 60 W * 3 h to kWh; full unit algebra through the lazy math engine.
• Multi-target — 10 km to mi, ft, m stacks every target in one card.
• Number bases — 255 to hex, bin, oct, 0xff to dec, 0b1010 to hex/dec.
• Numerals — integer ↔ words (English and Indian lakh/crore) and Roman numerals (1–3999) in a cross-filling tab; also in the smart bar via 1234 to words, 2026 to roman, mcmxcix to number, 2500000 to crore.
• Encode tab — text ↔ Base64, URL-encoding, and hex, Unicode-safe (emoji round-trip); edit any cell to decode and re-derive the rest.
• Type-once-fill-all grid — 16 categories including regional units (bigha, tola, gaj, maund…). Pin favourites to the top.
• Live currency — 35 currencies in the grid (160+ recognised in the smart bar), fetched keyless with a cached + bundled offline fallback; the grid shows the upstream timestamp and flags stale rates. Works in expressions too.
• Date tab — days between dates, add/subtract durations, timezone conversion across major zones, and Unix-epoch ↔ calendar (UTC).
• Notation — Auto / Decimal / Fraction / Indian / Scientific / Engineering, plus an adjustable significant-digits precision (2–10); INR results also show a lakh/crore hint.
• Fractions — a notation, not a tab, so it applies everywhere at once: 5.375 in reads 5 3/8 in across the smart bar, the grid and the sibling chips. Exact wherever an exact fraction exists under the cap (all the binary denominators imperial work needs, plus friendly ones like 1/3); otherwise it snaps to the nearest 1/64 and says ≈, never a fraction pretending to be exact. The precision stepper becomes the denominator cap (1/4 … 1/1024). One-off via 0.375 to fraction.
• Keyboard-first — type anywhere to focus, / to focus, ↑↓ through suggestions, Enter copies and logs to history, Esc clears.
• Shareable URLs — every result mirrors to ?q=… for copy-paste sharing.
• History — persisted, re-runnable, copyable, clearable.
• Dark "night almanac" theme — auto / light / dark toggle.

Tech

SvelteKit (adapter-static) · Svelte 5 runes · TypeScript · Bun · mathjs (lazy) · Vitest · Playwright.

Pure-TS logic modules (registry, parser, format, currency, date) power the grid and date math instantly with zero framework or math-library dependencies; mathjs is lazy-loaded only for smart-bar expressions.

Fonts are self-hosted (static/fonts) so the offline PWA keeps its typography — the service worker only caches same-origin assets. The help panel is a native <dialog>, so its focus trap, Esc handling and focus restore come from the platform rather than from app code.

Develop

bun install
bun run dev        # dev server
bun run check      # svelte-check (types)
bun run test       # unit tests (Vitest)
bun run test:e2e   # end-to-end (Playwright)
bun run build      # static site -> build/
bun run preview    # preview the production build