diff --git a/cs1811.css b/cs1811.css
index 05306eba968b006a5596a952e16ce3ee74d3c904..fcade79338f5c33ab982eba1b1765e45e552c46c 100644
--- a/cs1811.css
+++ b/cs1811.css
@@ -7,7 +7,7 @@
  */
 
 .step {
-    font-family: Sans;
+    font-family: sans-serif;
 }
 
 .step.concept {
diff --git a/templates/impress.cs/css/style.css b/templates/impress.cs/css/style.css
index 018a63aec0aa1d9797f661bdaf67f490f0da2360..dd62df75ef1845035e0ad1fac3dbe21bee9a0c94 100644
--- a/templates/impress.cs/css/style.css
+++ b/templates/impress.cs/css/style.css
@@ -47,7 +47,7 @@ table {
 }
 
 body {
-    font-family: Sans;
+    font-family: sans-serif;
     min-height: 740px;
 }
 
@@ -166,6 +166,10 @@ table {
      opacity: .1;
 }
 
+.step.invisible_future.future {
+    opacity: 0;
+}
+
 /*
  opacity issues for slide_steps
 */