fix: title wrapper margins (#632)

My #629 fixed side scrolling, but it turns out a 100% max-width also means no margins on narrow displays. This fixes both issues.

src/styles.css

@@ -1,6 +1,6 @@
 .iconize-inline-title-wrapper {
   width: var(--line-width);
-  max-width: 100%;
+  max-width: var(--max-width);
   margin-inline: var(--content-margin);
 }