diff --git a/templates/html/Wize_S5/ui/default/slides.js b/templates/html/Wize_S5/ui/default/slides.js
index 5183efd..6727632 100644
--- a/templates/html/Wize_S5/ui/default/slides.js
+++ b/templates/html/Wize_S5/ui/default/slides.js
@@ -398,8 +398,10 @@ function createControls() {
 
 function fontScale() {  // causes layout problems in FireFox that get fixed if browser's Reload is used; same may be true of other Gecko-based browsers
 	if (!s5mode) return false;
-	var vScale = 22;  // both yield 32 (after rounding) at 1024x768
-	var hScale = 32;  // perhaps should auto-calculate based on theme's declared value?
+	//var vScale = 22;  // both yield 32 (after rounding) at 1024x768
+	//var hScale = 32;  // perhaps should auto-calculate based on theme's declared value?
+	var vScale = Math.round(22 / getScaleFromTheme());
+    var hScale = Math.round(vScale * 32 / 22);
 	if (window.innerHeight) {
 		var vSize = window.innerHeight;
 		var hSize = window.innerWidth;
@@ -422,6 +424,12 @@ function fontScale() {  // causes layout problems in FireFox that get fixed if b
 	}
 }
 
+function getScaleFromTheme() {
+    var sc = parseFloat(getComputedStyle(document.documentElement).getPropertyValue('--main-pres-font-scale'));
+    sc = isNaN(sc) ? 1.0 : sc;
+    return sc;
+}
+
 function fontSize(value) {
 	if (!(s5ss = document.getElementById('s5ss'))) {
 		if (!isIE) {