Fixed bug with nav UI hiding on mobile

.htaccess

 AddCharset utf-8 .shtml .html .css .php .txt .js
 
-<filesMatch ".(css)$">
+# Disable caching of CSS and JS (for testing only).
+<filesMatch ".(css|js)$">
 	Header set Cache-Control "max-age=0, public"
 </filesMatch>
 

assets/js/script.js

 
 	// On desktop, show site nav UI when scrolling a full page up, or to the
 	// the top of the page.
-	// On mobile, show site nav UI translucent on ANY scroll up.
+	// On mobile, show site nav UI on ANY scroll up.
 	if (GW.mediaQueries.mobileNarrow.matches) {
-		if (GW.scrollState.unbrokenUpScrollDistance > 0)
+		if (GW.scrollState.unbrokenUpScrollDistance > 0 || GW.scrollState.lastScrollTop <= 0)
 			showSiteNavUI();
 	} else if (   GW.scrollState.unbrokenUpScrollDistance > window.innerHeight
-			 || GW.scrollState.lastScrollTop == 0) {
+			   || GW.scrollState.lastScrollTop == 0) {
 		showSiteNavUI();
 	}
 }