Fix date filter using month filter when year is all time and add background to stats section

src/ui/code-blocks/ReadingStatsCodeBlockView.svelte

@@ -167,12 +167,13 @@
 	.obt-reading-stats {
 		display: flex;
 		flex-direction: column;
-		gap: 1rem;
+		gap: var(--size-4-6);
 		max-width: 50rem;
 		margin: 0 auto;
 
 		.section {
 			padding: 0.5rem;
+			background-color: var(--background-secondary);
 			border: 1px solid var(--background-modifier-border);
 			border-radius: 0.5rem;
 

src/ui/stores/date-filter.svelte.ts

@@ -29,13 +29,13 @@ export function createDateFilter<T>(
 					if (date.year() !== filterYear) {
 						return false;
 					}
-				}
 
 					if (filterMonth !== ALL_TIME) {
 						if (date.month() !== filterMonth - 1) {
 							return false;
 						}
 					}
+				}
 				return true;
 			})
 			.sort((a, b) => selector(a).diff(selector(b)));