More specific solution...?

In the tasks "Change the background color of the submit button when active." and "Give the text field a blue border upon focus." there is a more specific solution than the one in the video...

For the first task this:

.subscribe input[value="Signup"]:active { background-color: red; }

And for the second this:

.subscribe input[placeholder="Enter email..."]:focus { border-style: solid; border-color: blue; }

Is this allright? It's working fine, I am just wondering is my solution gives unnecessary loading time, not so effective or something like this... and I'm not thinking about the styling...

Thank you for your answer!