This is most likely due to Chrome's caching of your files. Due to caching, you're seeing an old version of your styles. In incognito mode, this is not a problem because Chrome uses a fresh cache when you start a session and removes that cache when you end the session. You can solve your problem by clearing your cache.
In general, it's a good idea to test your application in incognito mode because it gives you a good idea what someone sees when they first visit a site, and it allows you to experience your application in a clean environment without any extensions or cache.