Documents/Pdf: allow double-sided pages to be printed

Elwig/Documents/style.css

@@ -57,6 +57,12 @@ header .type {
 .footer-wrapper {
     position: running(page-footer);
     width: 165mm;
+    /* for some reason the position without the following statement changes on the second page */
+    border: 0.5pt solid #00000000;
+}
+
+.footer-wrapper.left {
+    position: running(page-footer-left);
 }
 
 .pre-footer {
@@ -69,16 +75,16 @@ header .type {
     width: 33%;
 }
 
-.pre-footer .date {
+.pre-footer > *:first-child {
     text-align: left;
 }
 
-.pre-footer .doc-id {
+.pre-footer > *:nth-child(2) {
     text-align: center;
     font-style: italic;
 }
 
-.pre-footer .page {
+.pre-footer > *:last-child {
     text-align: right;
     float: right;
 }