style: align embeds with text content horizontal margins

- Add left/right margins of 2.25rem to match text block padding
- Ensure YouTube videos, link cards, and other embeds align with text
- Add responsive margins (2rem) for mobile viewports
- Fixes issue where embeds were too wide compared to text content

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/lib/components/edra/editor.css

@@ -582,6 +582,8 @@ input[type='checkbox'] {
 .tiptap .node-audio,
 .tiptap .node-geolocation {
 	margin-bottom: 1rem;
+	margin-left: 2.25rem;
+	margin-right: 2.25rem;
 }
 
 /* YouTube embeds within urlEmbed */
@@ -599,3 +601,16 @@ input[type='checkbox'] {
 .tiptap .edra-youtube-embed-wrapper + * {
 	margin-top: 0;
 }
+
+@media (max-width: 768px) {
+	.tiptap .node-urlEmbed,
+	.tiptap .node-iframe,
+	.tiptap .node-video,
+	.tiptap .node-image,
+	.tiptap .node-gallery,
+	.tiptap .node-audio,
+	.tiptap .node-geolocation {
+		margin-left: 2rem;
+		margin-right: 2rem;
+	}
+}