Fix flex property width of first column

client/components/cards/checklists.styl

@@ -56,7 +56,7 @@ textarea.js-add-checklist-item, textarea.js-edit-checklist-item
         border-right: 2px solid #3cb500
 
     .item-title
-      flex-grow: 1
+      flex: 1
       padding-left: 10px;
       &.is-checked
         color: #8c8c8c