fix: make the background opaque (sveltejs#440)

fixes sveltejs#439

Author: Dave-lab12

src/routes/tutorial/[slug]/filetree/ContextMenu.svelte

@@ -55,13 +55,18 @@
 	ul {
 		margin: 0;
 		padding: 0;
+		background-color: var(--sk-back-3);
+		border: 1px solid hsl(var(--sk-theme-1-hsl));
 	}
 
 	li {
 		display: block;
 		list-style-type: none;
 		width: 1fr;
 	}
+	li:hover {
+		background-color: var(--sk-theme-1-variant);
+	}
 
 	button {
 		color: var(--sk-text-2);