Over State Submit button

Nick, how would you add a hover state to the below css

.salesforce_w2l_lead .w2linput.submit {
float: none;
margin: .75em 0 0 0;
clear: both;
border-radius: 3px !important;
border-style: none;
margin-top:20px;
padding-top: 8px;
padding-bottom: 8px;
padding-left: 15px;
padding-right: 15px;
color:#ffffff !important;
background-image: linear-gradient(top, #264814 0%, #43a012 100%);
background-image: -o-linear-gradient(top, #264814 0%, #43a012 100%);
background-image: -moz-linear-gradient(top, #264814 0%, #43a012 100%);
background-image: -webkit-linear-gradient(top, #264814 0%, #43a012 100%);
background-image: -ms-linear-gradient(top, #264814 0%, #43a012 100%);
}

https://wordpress.org/plugins/salesforce-wordpress-to-lead/