Why doesn't focus effect work?

Hello, I need someone expirenced to take a look at my mini code. For some reason(which I can’t figure out what) nothing happends when I focus on my input.
Here’s the code and thanks in advance!

(the blue line at the bottom is supposed to grow to the full extent)

I don’t see any focus effect added to your CSS. What do you mean by a blue line? The input field is surrounded by a blue border by default when it’s clicked.