Change opacity of finished todos instead of background color

app/assets/stylesheets/pages/todos.scss

@@ -67,18 +67,27 @@
     flex: 0 1 100%;
     min-width: 0;
   }
-}
 
-.todos-list > .todo.todo-pending.done-reversible {
-  background-color: $gray-light;
+  &.todo.todo-pending.done-reversible {
+    background-color: $white-light;
 
     &:hover {
-    border-color: $border-color;
+      border-color: $white-normal;
     }
 
     .title {
       font-weight: normal;
     }
+
+    .todo-avatar,
+    .todo-item {
+      opacity: .2;
+    }
+
+    .btn {
+      background-color: $gray-light;
+    }
+  }
 }
 
 .todo-item {