---
phase: "17"
plan: "03"
subsystem: pwa/layout
tags: [layout-fix, fab-overlap, bottom-tab-bar, phone-only, regression-guard, css-tokens, d-01, d-02]
dependency_graph:
  requires:
    - apps/pwa/src/styles/tokens.css — --bottom-chrome-h token (provided by plan 17-01)
  provides:
    - FAB overlap fix: CalendarShell.tsx FAB bottom = calc(var(--bottom-chrome-h) + var(--space-6))
    - Phone content padding: App.tsx contentStyle paddingBottom = var(--bottom-chrome-h) (phone-only)
    - Regression guard: apps/pwa/e2e/layout.spec.ts — D-01 overlap assertion (iphone + pixel)
  affects:
    - apps/pwa/src/components/CalendarShell.tsx (FAB bottom offset)
    - apps/pwa/src/App.tsx (contentStyle paddingBottom)
    - apps/pwa/e2e/layout.spec.ts (new overlap assertion)
tech_stack:
  added: []
  patterns:
    - "CSS calc() combining --bottom-chrome-h token with --space-6 for FAB clearance above BottomTabBar"
    - "Spread pattern ...(phone ? { paddingBottom: var(--bottom-chrome-h) } : {}) for phone-only contentStyle"
    - "Playwright boundingBox() geometry assertion: fabBox.y + fabBox.height <= navBox.y"
key_files:
  created: []
  modified:
    - apps/pwa/src/components/CalendarShell.tsx
    - apps/pwa/src/App.tsx
    - apps/pwa/e2e/layout.spec.ts
decisions:
  - "FAB bottom uses calc(var(--bottom-chrome-h) + var(--space-6)) — positions FAB 24px above bar top edge regardless of safe-area-inset value"
  - "contentStyle paddingBottom is phone-only via spread pattern — desktop has no BottomTabBar and must not gain extra bottom padding (RESEARCH Pitfall 2)"
  - "Overlap assertion skips desktop profile — the desktop New Event button is a toolbar button, not the FAB; geometry check is semantically wrong for sidebar layout"
  - "Full e2e suite run on all three profiles confirmed zero regressions from layout changes"
metrics:
  duration: "~18 minutes"
  completed_date: "2026-06-18"
  tasks_completed: 3
  tasks_total: 3
  files_changed: 3
status: complete
---

# Phase 17 Plan 03: Phone Layout Overlap Fix — Summary

Fixed the long-standing phone (≤767px) fixed-chrome overlap where the `position: fixed` BottomTabBar was covering the New Event FAB and occluding the bottom color-legend chips, using the `--bottom-chrome-h` token from plan 17-01. Added a permanent D-01 overlap regression assertion to `layout.spec.ts`. Full 3-profile Playwright suite is green.

## What Was Built

**One-liner:** FAB lifted above BottomTabBar via `calc(var(--bottom-chrome-h) + var(--space-6))`, phone content reserves `--bottom-chrome-h` padding, permanent overlap regression guard added to CI.

### Task 1: FAB lift + phone content padding (CalendarShell.tsx, App.tsx)

**CalendarShell.tsx** (phone-only FAB, lines 463–491):
- Changed `bottom: 'var(--space-6)'` → `bottom: 'calc(var(--bottom-chrome-h) + var(--space-6))'`
- FAB now sits 24px (var(--space-6)) above the BottomTabBar top edge regardless of safe-area-inset
- All other FAB style properties unchanged (right, width, height, zIndex, etc.)

**App.tsx** (contentStyle, lines 155–164):
- Added phone-only spread: `...(phone ? { paddingBottom: 'var(--bottom-chrome-h)' } : {})`
- Phone content area now reserves space equal to the BottomTabBar height
- Desktop branch has no paddingBottom — geometry unchanged
- Build: `pnpm --filter @familysync/pwa build` exits 0

### Task 2: FAB↔BottomTabBar overlap regression assertion (layout.spec.ts)

Added new `test.describe` block "D-01 regression guard — FAB does not overlap BottomTabBar":
- Test name: "New Event FAB does not overlap BottomTabBar (A — phone only)"
- Skips on desktop (`testInfo.project.name === 'desktop'`)
- Locates FAB via `page.getByRole('button', { name: 'New Event' })` and bar via `page.getByRole('navigation', { name: 'Main navigation' })`
- Asserts `fabBox.y + fabBox.height <= navBox.y` (FAB bottom ≤ BottomTabBar top)
- Passes GREEN on iphone (390×844 WebKit) and pixel (412×915 Chromium)

### Task 3: Small-viewport sweep across all three profiles

- `pnpm --filter @familysync/pwa test:e2e` (all 3 profiles): **115 passed, 23 skipped, 0 failed**
  - iphone profile: all layout.spec.ts assertions pass including new D-01 guard
  - pixel profile: all layout.spec.ts assertions pass including new D-01 guard
  - desktop profile: all layout.spec.ts assertions pass; D-01 guard correctly skipped
- No violations flagged by Rules 1–4 assertions
- Admin tab tap target still meets ≥44px after layout changes
- Color-legend chips confirmed fully visible via playwright-cli screenshot at 390×844

## Visual Confirmation (playwright-cli @390×844)

Screenshot taken via playwright-cli (Chromium, viewport 390×844, reloaded to pick up phone layout):
- **New Event FAB (+)**: clearly positioned above the BottomTabBar with visible gap
- **Color-legend chips** ("Dev User" blue, "Family" pink): fully visible between calendar content and BottomTabBar — not clipped or occluded
- **BottomTabBar** (Calendar, Lists, Admin): fully visible at the bottom edge

## Verification Results

| Check | Result |
|-------|--------|
| `grep 'calc(var(--bottom-chrome-h) + var(--space-6))'` in CalendarShell.tsx | PASS |
| `grep "paddingBottom: 'var(--bottom-chrome-h)'"` in App.tsx | PASS |
| `grep 'New Event FAB does not overlap BottomTabBar'` in layout.spec.ts | PASS |
| `pnpm --filter @familysync/pwa build` | PASS |
| Playwright iphone + pixel layout.spec.ts (overlap assertion) | PASS — 32 passed, 2 skipped |
| Full 3-profile `pnpm --filter @familysync/pwa test:e2e` | PASS — 115 passed, 23 skipped, 0 failed |
| playwright-cli visual confirmation @390×844 | PASS — FAB above bar, legend chips visible |
| Desktop geometry unchanged | PASS — no desktop layout changes |

## Deviations from Plan

None. Plan executed exactly as written. The three-task sequence (CSS fix, regression guard, sweep) was completed without any deviations. The FAB bottom value, phone contentStyle spread pattern, and overlap assertion all match the plan specification exactly.

## Known Stubs

None. All changes are wired and fully functional.

## Threat Flags

None. CSS-only layout offsets plus a Playwright geometry test — no new network endpoints, auth paths, or data flows introduced.

## Self-Check: PASSED

| Item | Result |
|------|--------|
| CalendarShell.tsx exists | FOUND |
| App.tsx exists | FOUND |
| layout.spec.ts exists | FOUND |
| SUMMARY.md exists | FOUND |
| Commit 5e1c714 (Task 1) | FOUND |
| Commit 85a803f (Task 2) | FOUND |
| CalendarShell FAB bottom grep | PASS |
| App.tsx paddingBottom grep | PASS |
| layout.spec.ts overlap assertion grep | PASS |
