# Story 9.9: Responsive Design Implementation

## Epic Reference
**Epic 9:** Design & Branding Implementation

## User Story
As a **user**,
I want **the platform to work perfectly on all device sizes**,
So that **I can use it on my phone, tablet, or desktop**.

## Acceptance Criteria

### Breakpoints
- [ ] Mobile: < 576px
- [ ] Tablet: 576px - 991px
- [ ] Desktop: 992px - 1199px
- [ ] Large Desktop: >= 1200px

### Mobile Optimizations
- [ ] Touch-friendly targets (44px+)
- [ ] Readable font sizes
- [ ] Single column layouts
- [ ] Collapsible sections

### Tablet Optimizations
- [ ] Two-column where appropriate
- [ ] Sidebar collapsible

### Desktop Optimizations
- [ ] Full layouts with sidebars
- [ ] Multi-column grids

### Specific Features
- [ ] All forms usable on mobile
- [ ] Calendar usable on mobile
- [ ] Tables scroll horizontally
- [ ] No horizontal scroll on any viewport

## Technical Notes

```css
/* Mobile-first approach */
.dashboard-grid {
  @apply grid gap-4;
  @apply grid-cols-1; /* Mobile */
  @apply sm:grid-cols-2; /* Tablet */
  @apply lg:grid-cols-3; /* Desktop */
  @apply xl:grid-cols-4; /* Large */
}

/* Touch targets */
.touch-target {
  @apply min-h-[44px] min-w-[44px];
}

/* Responsive table wrapper */
.table-responsive {
  @apply overflow-x-auto -mx-4 px-4;
}

/* Collapsible sidebar */
@media (max-width: 991px) {
  .sidebar {
    @apply fixed inset-y-0 start-0 w-64 transform -translate-x-full transition-transform z-40;
  }
  .sidebar.open {
    @apply translate-x-0;
  }
}
```

### Testing Devices
- iPhone SE (375px)
- iPhone 14 (390px)
- iPad (768px)
- iPad Pro (1024px)
- Desktop (1280px)
- Large Desktop (1920px)

## Definition of Done
- [ ] Mobile layout works
- [ ] Tablet layout works
- [ ] Desktop layout works
- [ ] No horizontal scroll
- [ ] Touch targets 44px+
- [ ] Forms usable on mobile
- [ ] Calendar usable on mobile
- [ ] Tests pass

## Estimation
**Complexity:** High | **Effort:** 5-6 hours