Custom CSS: How to change the font size of links under Image Radio Buttons?

I'm using the "Image Radio Buttons" widget. How to Change the font size of link text under Image Radio Buttons?

I tried adding the following css but it did not work:

.li label {

    font-size: 10px;

}

.li {

    font-size: 10px;

}

Please try the following CSS instead.

li > label > span {

    font-size: 10px !important;

}

Since it is a widget, add the CSS directly to the widget by following the steps below.

That worked, thanks!