Do we need prefix on the server?

scripts/templates/book.html

@@ -125,6 +125,7 @@
     .sentence {
       z-index: 1;
       position: relative;
+      background: -webkit-linear-gradient(to top, rgba(255,255,255,0), white 2.5em);
       background: linear-gradient(to top, rgba(255,255,255,0), white 2.5em);
       padding: 0.5em 20mm 3em 20mm;
       width: 100%;
@@ -135,6 +136,7 @@
     .tree {
       z-index: 1;
       position: relative;
+      background: -webkit-linear-gradient(to top, rgba(255,255,255,0), white 2.5em);
       background: linear-gradient(to bottom, rgba(255,255,255,0), white 2.5em);
       padding: 3em 20mm 0.5em 20mm;
       width: 100%;