try this. i added line-height and padding
@import url(http://fonts.googleapis.com/css?family=Libre+Baskerville:700);
input[type=submit] {
background: #CDA91B;
border: 0;
color: #FFF;
font-family: "Libre Baskerville", Libre Baskerville, Times New Roman, Times, serif;
font-size: 20px;
font-weight: 700;
line-height: 12px;
margin: 0;
padding: 25px;
text-transform: lowercase;
/* css3 */
-webkit-transition: background 0.25s;
-moz-transition: background 0.25s;
-ms-transition: background 0.25s;
-o-transition: background 0.25s;
transition: background 0.25s;
}
input[type=submit]:hover {
background: #E5BE1E;
cursor: pointer;
}