How to make a line width the same as a sentence above the line?

Question

I want it to look like this:

Sentence
_________

Answer 1

set bottom padding

Answer 2

padding-bottom:1px;
Change the pixel size and you are done

Answer 3

Thx

Answer 4

But padding of sentence?

Answer 5

First of all, set text decoration on your text div:

div {
text-decoration:underline;
}

Answer 6

Change The Píxel