如何使用tab函数和jQuery关注列表元素

I am working on a questionnaire for a client. They want the active question that is on focus to be at 100% opacity while the other inactive questions are at 20% opacity. Currently I have the page load, the questions dim to 20% opacity and the first question is at 100%. When I am done with a question and tab to the next question, that active list element stays at 20% opacity until I actually click the list element and/or the input field. How do I make the field or list element active and 100% opacity. Here is what I have so far:I am working on a questionnaire for a client. T