diff --git a/app/assets/stylesheets/conversation.css b/app/assets/stylesheets/conversation.css
index 0ee03fa59..95641849c 100644
--- a/app/assets/stylesheets/conversation.css
+++ b/app/assets/stylesheets/conversation.css
@@ -96,6 +96,7 @@
     display: flex;
     flex-direction: column;
     gap: var(--block-space);
+    inline-size: 100%;
     margin-inline: auto;
     max-inline-size: 67ch;
   }