revert from flexbox for pdf centering, use js for PDF setup

css/print/pdf.css

@@ -17,8 +17,6 @@
 
 body {
 	font-size: 18pt;
-	width: 297mm;
-	height: 229mm;
 	margin: 0 auto !important;
 	border: 0;
 	padding: 0;
@@ -105,8 +103,6 @@ ul, ol, div, p {
 	overflow: visible;
 	display: block;
 
-	text-align: center;
-
 	-webkit-perspective: none;
 	   -moz-perspective: none;
 	    -ms-perspective: none;
@@ -118,21 +114,15 @@ ul, ol, div, p {
 	        perspective-origin: 50% 50%;
 }
 .reveal .slides section {
-
 	page-break-after: always !important;
 
 	visibility: visible !important;
 	position: relative !important;
-	width: 100% !important;
-	height: 229mm !important;
-	min-height: 229mm !important;
 	display: block !important;
-	overflow: hidden !important;
+	position: relative !important;
 
-	left: 0 !important;
-	top: 0 !important;
 	margin: 0 !important;
-	padding: 2cm 2cm 0 2cm !important;
+	padding: 0 !important;
 	box-sizing: border-box !important;
 
 	opacity: 1 !important;
@@ -154,30 +144,6 @@ ul, ol, div, p {
 	height: auto !important;
 	min-height: auto !important;
 }
-.reveal .absolute-element {
-	margin-left: 2.2cm;
-	margin-top: 1.8cm;
-}
-.reveal section .fragment {
-	opacity: 1 !important;
-	visibility: visible !important;
-
-	-webkit-transform: none !important;
-	   -moz-transform: none !important;
-	    -ms-transform: none !important;
-	        transform: none !important;
-}
-.reveal section .slide-background {
-	position: absolute;
-	top: 0;
-	left: 0;
-	width: 100%;
-	z-index: 0;
-}
-.reveal section>* {
-	position: relative;
-	z-index: 1;
-}
 .reveal img {
 	box-shadow: none;
 }
@@ -189,11 +155,17 @@ ul, ol, div, p {
 	font-size: 16pt !important;
 }
 
-.reveal.center .slides section:not(.stack) {
-	display: flex !important;
-	flex-direction: column;
-	align-items: center;
-	justify-content: center;
-	padding-top: 2em !important;
-	padding-bottom: 2em !important;
+/* Slide backgrounds are placed inside of their slide when exporting to PDF */
+.reveal section .slide-background {
+	position: absolute;
+	top: 0;
+	left: 0;
+	width: 100%;
+	z-index: 0;
 }
+/* All elements should be above the slide-background */
+.reveal section>* {
+	position: relative;
+	z-index: 1;
+}
+

css/reveal.css

@@ -1328,6 +1328,8 @@ body {
 	position: absolute;
 	width: 100%;
 	height: 100%;
+	top: 0;
+	left: 0;
 
 	-webkit-perspective: 600px;
 	   -moz-perspective: 600px;