diff --git a/assets/css/main.css b/assets/css/main.css
index 781046d30..79265fa57 100755
--- a/assets/css/main.css
+++ b/assets/css/main.css
@@ -4014,6 +4014,7 @@ cite {
 
 .chapters .chapter img {
   width: 100%;
+  height: 100%
   vertical-align: middle;
   -webkit-transition: all 0.4s;
   transition: all 0.4s;