Text size

My website address is redarrowsc.com. I am new to design. I have used this forum and tutorials in codex trying to learn. I am using Singl. I have a child theme and in that theme I have the following:.hentry
{
background-color: transparent;
text-shadow: 1px 1px gray;
text-size: 200%;
}

The text does not change size as I adjust the value. I am trying to make the text in the Welcome statement on the front page larger. Can anyone help or give me a link that will explain how to do that?

Thanks