In your CSS file, you are missing the closing curly brace on your
.learn-more h3 rule. Maybe you are missing other vital punctuation, I don't know because you didn't post all of your CSS file.
Your shift.css link looks okay, but I can't test it for you because you've posted an image instead of text.
If you need more help, please post your code so that it can be copy/pasted.
If you need it: How to post code in this forum.