## Purpose

Canonical specification for modal-layout-and-loading-feedback requirements synced from OpenSpec change deltas.

## Requirements

### Requirement: Modal width supports comfortable desktop reading
The summary modal SHALL render with a desktop width that is approximately half of viewport width or larger when space allows, while remaining responsive on small screens.

#### Scenario: Desktop width expansion
- **WHEN** the modal opens on desktop viewport widths
- **THEN** the modal content area renders wider than the previous narrow baseline
- **AND** text blocks are readable without excessive line wrapping

#### Scenario: Mobile responsiveness
- **WHEN** the modal opens on small mobile viewport widths
- **THEN** modal width remains fully usable without horizontal overflow

### Requirement: Modal height supports near-full viewport scrolling
The summary modal SHALL use near full-height viewport behavior when content overflows.

#### Scenario: Overflowing summary content
- **WHEN** summary content exceeds modal viewport height
- **THEN** modal body remains scrollable with close controls accessible
- **AND** modal container uses near full viewport height constraints

### Requirement: TL;DR loading placeholder is explicit
The modal SHALL show a horizontal shimmer placeholder for TL;DR content while TL;DR bullets are not yet available.

#### Scenario: TL;DR pending state
- **WHEN** the summary modal is open and TL;DR bullet data is pending
- **THEN** the system displays a low-height horizontal shimmer placeholder

#### Scenario: TL;DR loaded state
- **WHEN** TL;DR bullet data becomes available
- **THEN** shimmer placeholder is removed
- **AND** TL;DR bullet list is rendered