---
id: TASK-038
title: 'Fix: mouse checkbox toggle off-by-one (click lands one row below)'
status: "\U0001F3C1 Done"
assignee: []
created_date: '2026-07-06 18:51'
updated_date: '2026-07-06 18:55'
labels:
  - bug
dependencies: []
priority: high
ordinal: 37000
---

## Description

<!-- SECTION:DESCRIPTION:BEGIN -->
handleMouse vi = Scroll + msg.Y - topPad + 1 has a spurious +1. Every left click maps one visual row too low; checkbox toggle only worked when the box was the last visual row (MoveToVisual clamp rescued it). Drop the +1.
<!-- SECTION:DESCRIPTION:END -->

## Acceptance Criteria
<!-- AC:BEGIN -->
- [x] #1 Clicking a checkbox glyph on any row toggles that row's box
- [x] #2 Regression test covers a mid-document checkbox with rows below it
<!-- AC:END -->