error in codeigniter 3.1.2

hi, i am really new to codeigniter. i started it with a login form. i used https://www.formget.com/form-login-codeigniter/ instructions. But i couldn't make that one. My codeigniter is at xampp->htdocs->ci. and i placed all the pages according to the above mentioned link. but when i runs localhost//ci/ , it shows this error An Error Was Encountered Unable to load the requested class: Login. 


what should i do? can somebody help me to solve this. i am a beginner. or somebody gave me instructions to create a simple login page?!!!

That "tutorial" appears targetted to CodeIgniter 2, judging by the controller filenames it suggests (all lower case).
Class files in CI3 need their filenames UCfirst, eg. controllers/Login.php and not controllers/login.php