html ,body{
    height: 100%;
}
body{
    background-color: #F2F2F2; 
    padding-top: 100px;
    background-image: url(../img/bg0.jpg);
    }
 /*btn*/
 .u-btn-gray{
  background-color: #AEAEAE;
  color: #FFFFFF; 
 }