feat(gallery): enhance close button accessibility

Add .navClose styles for 30% min-width, right alignment, and pointer cursor.
Apply class to close div in mobile gallery nav for consistent keyboard support.

Signed-off-by: Sped0n <hi@sped0n.com>

assets/scss/_partial/_gallery.scss

@@ -51,6 +51,12 @@
     display: flex;
     justify-content: space-between;
     align-items: center;
+
+    .navClose {
+      min-width: 30%;
+      text-align: right;
+      cursor: pointer;
+    }
   }
 }