diff --git a/src/app.css b/src/app.css
index 50a44089..8ca86b88 100644
--- a/src/app.css
+++ b/src/app.css
@@ -409,6 +409,7 @@ a.mention span {
 
 .decks {
   flex-grow: 1;
+  width: 100%;
 }
 
 .deck-close {