## Why

Content cards on the homepage, videos page, and podcast page currently link directly to YouTube/Spotify as outbound links (`target="_blank"`). Every click immediately sends the user off-site, inflating bounce rate and cutting short time-on-site. Embedding media in an in-page modal keeps users on the site longer while still providing clear CTAs to the canonical platform when they're ready.

## What Changes

- **Content cards become modal triggers instead of outbound links.** Clicking a video or podcast card on the homepage, `/videos`, or `/podcast` opens a modal dialog with an embedded player — the user stays on-site.
- **New modal dialog component.** An accessible modal overlay that renders:
  - Title (top-left) and a close button (top-right)
  - Embedded YouTube iframe or Spotify embed player (based on content source)
  - Description / summary text
  - Date and view count (live count if YouTube API key is configured)
  - "Follow on YouTube/Spotify" CTA and "View on YouTube/Spotify" CTA
- **Playback lifecycle tied to modal.** Closing the modal (close button or `Escape` key) MUST stop media playback — no audio/video continues after the modal is dismissed.
- **Umami event taxonomy update.** Card clicks on listing pages are no longer outbound — event names change from `outbound_click` to a new interaction event. New events are added for modal open, modal close, follow CTA, view-on-platform CTA, and (stretch) engagement duration.

## Capabilities

### New Capabilities
- `media-modal`: Accessible modal dialog component that embeds YouTube/Spotify players, displays content metadata, provides platform CTAs, and manages playback lifecycle (stop on close/escape).

### Modified Capabilities
- `card-layout-system`: Cards for video/podcast content become modal triggers instead of outbound `<a>` links. The card visual layout stays the same; the interaction target changes.
- `interaction-tracking-taxonomy`: Card clicks are no longer `outbound_click` — a new event category is needed for in-page media previews. New tracked interactions: modal open, modal close, modal CTA clicks (follow, view-on-platform). Stretch: engagement duration tracking.
- `analytics-umami`: New event names and properties must be emitted for modal interactions using the existing `data-umami-event-*` attribute pattern.
- `conversion-ctas`: New CTA instances inside the modal ("Follow on YouTube/Spotify", "View on YouTube/Spotify") must follow the existing `CtaLink` tracking conventions.

## Impact

- **Components**: `ContentCard.astro`, `StandardCard.astro` — card click behavior changes from outbound link to modal trigger on video/podcast sources (Instagram cards are unaffected).
- **New component**: A `MediaModal` component (likely client-side JS/Astro island) for the dialog, embed player, and playback control.
- **Pages**: `index.astro`, `videos.astro`, `podcast.astro` — must mount the modal and wire card click handlers.
- **Analytics**: All `data-umami-event="outbound_click"` on video/podcast content cards change to a non-outbound event. New events added for modal interactions.
- **Accessibility**: Modal must follow WCAG 2.2 AA patterns already established in `wcag-responsive-ui` spec — focus trap, `Escape` to close, `aria-modal`, focus return on dismiss.
- **No backend changes.** Content ingestion, caching, and data model (`ContentItem`) are unchanged. YouTube embed IDs are derivable from existing `item.url`. Spotify embed URLs are derivable from existing `item.url`.
- **No breaking changes.** Detail pages (`/videos/[id]`, `/podcast/[id]`) remain as-is for SEO/sharing. The modal is an additive UX layer on listing surfaces only.