hide parked map attribution, back link on activity page

src/routes/+layout.svelte

@@ -302,7 +302,10 @@
 		left: 0;
 		width: 720px;
 		height: 440px;
+		/* visibility alone leaks maplibre children that set their own visibility */
 		visibility: hidden;
+		opacity: 0;
+		overflow: hidden;
 		pointer-events: none;
 		z-index: -1;
 	}

src/routes/activities/[id]/+page.svelte

@@ -37,6 +37,8 @@
 	<title>{a.name} · Streba</title>
 </svelte:head>
 
+<a class="back" href="/">← Overview</a>
+
 <div class="head">
 	<div>
 		<h1>{a.name}</h1>
@@ -102,6 +104,21 @@
 {/if}
 
 <style>
+	.back {
+		display: inline-block;
+		margin-bottom: 0.75rem;
+		font-size: 0.85rem;
+		font-weight: 500;
+		color: var(--text-secondary);
+		text-decoration: none;
+		padding: 0.25rem 0.6rem;
+		margin-left: -0.6rem;
+		border-radius: 0.45rem;
+	}
+	.back:hover {
+		background: var(--wash);
+		color: var(--text-primary);
+	}
 	.head {
 		display: flex;
 		justify-content: space-between;