Unequal Dice Sum Explorer

Goal Build a tiny offline probability tool that reveals the exact sum distribution for two fair dice, including dice with different numbers of sides. Deliverable Submit exactly one self-contained file named index.html, no larger than 35 KB. It must work when opened locally without a server or internet connection. Observable requirements 1. Provide integer side-count controls for Die A and Die B from 4 through 12 inclusive, defaulting both to 6. 2. Enumerate the exact ordered outcomes and calculate the frequency of every possible sum from 2 through A+B; do not estimate by random simulation. 3. Display every sum in an accessible table or table-plus-bar view with its outcome count, reduced fraction over A times B, and percentage rounded consistently to no more than 2 decimal places. 4. Provide a target-sum control constrained to the current valid range. Highlight that sum and show its count, reduced fraction, and percentage separately. 5. Update all results immediately when either die or the target changes, and display the total number of equally likely ordered outcomes. 6. Pass these checks: 6+6 gives sum 7 as 6/36 and 16.67%; 4+6 gives sum 5 as 4/24 and 16.67%; all displayed counts add to A times B. 7. Make bar lengths proportional to probability and distinguish values with text or shape, not color alone. 8. Use labelled keyboard-operable controls, visible focus, strong contrast, a live result announcement, and a clear layout from 360 to 1200 CSS pixels wide. Include one short explanation of the fair-independent-dice assumption. Negative scope No random-roll simulator, external libraries, fonts, images, network requests, storage, clipboard access, tracking, accounts, uploads, gambling advice, or additional files. Pass/fail acceptance gates - The only deliverable is index.html and it is 35 KB or smaller. - It works fully offline and contains no network, storage, or simulation code. - Side ranges, sum ranges, counts, reduced fractions, percentages, target behavior, and the three representative checks are exact. - Controls and results are keyboard accessible, labelled, visibly focused, responsive, and understandable without color alone. - The total-outcomes display and fair-dice explanation are present. Scoring rubric (100 points, in order) 1. Probability and interaction correctness: 45 points. 2. Artifact, range, and negative-scope compliance: 25 points. 3. Accessibility and explanatory clarity: 20 points. 4. Visual craft and responsive polish: 10 points. Tie-breaker Prefer the submission whose enumeration, fraction reduction, and representative checks are easiest to verify from readable code and direct interaction; then prefer stronger accessibility. Visual styling is creatively open outside the mandatory core.