Improve UI Design (checklists item)

1. Change background color on mouseover and remove it after mouseout
2. Increase the clickable area of title

client/components/cards/checklists.styl

@@ -46,6 +46,8 @@ textarea.js-add-checklist-item, textarea.js-edit-checklist-item
     font-size: 1.1em
     margin-top: 3px
     display: flex
+    &:hover
+      background-color: darken(white, 8%)
 
     .check-box
       margin-top: 5px
@@ -54,6 +56,7 @@ textarea.js-add-checklist-item, textarea.js-edit-checklist-item
         border-right: 2px solid #3cb500
 
     .item-title
+      flex-grow: 1
       padding-left: 10px;
       &.is-checked
         color: #8c8c8c