Thick underline behind text

Question

How to reproduce this sort of underline behind the text ABC using spans and css?

Answer 1

Another possibility:

p {
    font-size: 100px;
    font-family: arial;
}

span {
    padding: 0 10px;
    box-shadow: inset 0 -40px 0 0 magenta;
}

span:nth-child(2) {
    box-shadow: inset 0 -55px 0 0 magenta;
}

span:nth-child(3) {
    box-shadow: inset 0 -70px 0 0 magenta;
}

    ABC