In your HTML source code I can see this:
<style type='text/css'>
body , .content { font-family: 'Lucida Sans', Arial , sans-serif;
font-size:11px;
font-style:normal;
;
background-repeat:repeat;
background-position: center center;
}
.custom-font { font-family: 'Sanchez', sans-serif; }
div.content div.two-third-width div.single-content , div.content div.two-third-width div.single-content p { color:#666666!important;}
.sticky-notice { background-color:#00000 ; }
.sticky-notice a.main-link { background-color:#99AD66 ; color:#ffffff; border:1px solid #3f6175; }
.sticky-notice .main-text { color:#ffffff; }
.content h1 { font-size:36px; }
.content h2 { font-size:32px; }
.content h3 { font-size:28px; }
.content h4 { font-size:24px; }
.content h5 { font-size:18px; }
.content h6 { font-size:13px; }
/* == ~~ This is the dynamic CSS ==================== */
/* == ~~ End of dynamic CSS ========================= */
Do you have some sort of CSS editor or plugin that might be doing this? Or perhaps the font size is in your theme options?