Keep the words to a column in the middle when stacked

Between a phone and the side-by-side layout, the request sat against the
left edge with the rest of the screen empty beside it. The title, request
and GitHub link now share a column as wide as the title, centred, with
the link hung from the same edge as the rest; the bridge still runs edge
to edge.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: teemingc

src/routes/+page.svelte

@@ -515,16 +515,28 @@
 			--drop: 0px;
 		}
 
+		/* Wider than a phone, the words keep to a column in the middle as wide as the title,
+		   so the request isn't left against one side with the screen empty beside it; the
+		   bridge still runs edge to edge */
+		header,
+		.request,
+		.github {
+			justify-self: center;
+			width: 100%;
+			max-width: 32rem;
+		}
+
 		/* Across the whole screen, so only its top edge is soft */
 		:global(:root:is([data-sky='dawn'], [data-sky='dusk'])) .page::before {
 			grid-column: 1 / -1;
 			margin-inline: -1.5rem;
 			mask-image: linear-gradient(var(--ease));
 		}
 
+		/* Hung from the same edge as everything above it */
 		.github {
 			align-self: end;
-			justify-content: center;
+			justify-content: flex-start;
 			padding-top: 1.5rem;
 		}
 	}