diff --git a/styles/h5p.css b/styles/h5p.css
index ea999df..d95af3e 100644
--- a/styles/h5p.css
+++ b/styles/h5p.css
@@ -36,6 +36,10 @@ html.h5p-iframe .h5p-content {
   width: 100%;
   height: auto;
 }
+html.h5p-iframe .h5p-fullscreen .h5p-content,
+html.h5p-iframe .h5p-semi-fullscreen .h5p-content {
+  height: 100%;
+}
 .h5p-content.h5p-no-frame,
 .h5p-fullscreen .h5p-content,
 .h5p-semi-fullscreen .h5p-content {