Double-click (desktop) or double-tap (mobile) any foreign word below. Its English translation appears on a card above it — holds long enough to read, then auto-fades over ~5 seconds on an S-curve. No second click. Double-click again to re-see it. Words look like normal text until you double-click them — no underlines, no popups by accident.
Each pair is a separate compact file, lazy-loaded on demand — your device only downloads the one it needs.
Zero-config: the snippet reads your device language and loads the matching pair automatically (English/unknown → Spanish default).
v1 translates single words, exact match (case-insensitive). Inflected forms not in the pack don't translate — that's an honest v1 boundary, not a bug. Chinese works through double-click selection (no word boundaries to pre-wrap). Data: Wiktionary via kaikki.org, CC-BY-SA 4.0 (see README for attribution).