Six-Dot Braille Cell Decoder

Goal Build a tiny offline tool that lets a user toggle the six dots in a braille cell and inspect the corresponding Unicode Braille Pattern character. Deliverable Submit exactly one self-contained file named index.html, no larger than 30 KB. It must work when opened locally without a server or internet connection. Observable requirements 1. Present six controls in standard braille-cell layout: dots 1-3 in the left column from top to bottom and dots 4-6 in the right column from top to bottom. 2. Toggling a dot must update the Unicode Braille Patterns character using the correct bit values: dots 1-6 map to 1, 2, 4, 8, 16, and 32 added to U+2800. 3. Always display the current glyph, its uppercase U+28XX code point, and the active dot numbers in ascending order or the word none. 4. Start at blank U+2800 and include a Clear control that restores that state. 5. Make on and off states distinguishable by more than color alone. 6. Use keyboard-operable native controls, visible focus, accessible labels, and a live announcement for changed output. 7. Remain clear and usable from 360 to 1200 CSS pixels wide with strong text/background contrast. 8. Include a short factual note that this decodes six-dot Unicode Braille patterns, not Grade 2 contractions or full braille transcription. Negative scope No external assets, libraries, fonts, network requests, storage, clipboard access, uploads, tracking, accounts, translation claims, or additional files. Pass/fail acceptance gates - The only deliverable is index.html and it is 30 KB or smaller. - It works fully offline and contains no network or storage code. - Representative mappings are exact: none is U+2800, dot 1 is U+2801, dots 1 and 4 are U+2809, and all six dots are U+283F. - All six controls are keyboard operable, labelled, visibly focused, and arranged in the correct numbered layout. - The glyph, code point, active-dot output, Clear behavior, factual note, and responsive layout are present. Scoring rubric (100 points, in order) 1. Mapping and interaction correctness: 45 points. 2. Artifact and negative-scope compliance: 25 points. 3. Accessibility and output clarity: 20 points. 4. Visual craft and responsive polish: 10 points. Tie-breaker Prefer the submission whose Unicode mapping and offline behavior are easiest to verify from readable code and direct interaction; then prefer stronger accessibility. Visual styling is creatively open outside the mandatory core.