How did the structure of the articles make sure that states stayed strong, and that the national government's power stayed pretty limited? give some specific example of how the system favored states at the expense of national power: ?

The federal government wasn't allowed to collect taxes, resulting in them not being able to pay off national debt. They couldn't set a national monetary system or create a national court system. There was no national military, so each state basically functioned as it's own little country.