It usually looks something like this in the CSS…
body.fs1 {
font-size: 10px;
}
body.fs2{
font-size: 11px;
}
body.fs3{
font-size: 12px;
}
body.fs4{
font-size: 13px;
}
body.fs5{
font-size: 14px;
}
where .fs3 would be the default sixe. But if you haven’t already changed these then that is not the problem. On templates tools font resizer there are usually 3 buttons Bigger, Default, and Smaller. If you press the default button then that should give you the default font size (ie. the one the template had when you installed it) if this is not the size the font originally had then you have changed it somewhere else. Make sure you haven’t just adjusted it on your browser (CTRL+mouse wheel)