Accessibility Fix: Measuring HTML Repair Without Content Loss

Accessibility Fix measures whether an HTML repair corrects injected defects while retaining page content. We study 40 public synthetic pages using scripted controls and a simulated population sweep. The reference pages receive full credit on every task; unchanged pages, empty answers, and refusals receive none. A template fixer earns mean 0.788 [0.713, 0.869] with a stratified bootstrap interval. The grader rejects reference pages modified with display:none, but accepts the same references modified with clip-path concealment. A simulated gate ablation measures the credit retained when the automatic-zero gate is removed. These experiments characterize a static repair score, not complete accessibility, user benefit, or learned-model ability. No learned model or human study is included.