a, 
input[type=submit]{
    cursor: pointer;
    text-decoration: none;
}
.left{
    float:left;
}
.right{
    float:right;
}
.clear{
    clear:both;
}
.hidden{
    display:none;
}
.center-text{
    text-align: center;
}
.expand{
    width:100%;
    height:100%;
}
.clean-bottom{
    margin-bottom: 10px;
}
.clean-top{
    margin-top: 10px;
}
@media screen and (min-width:480px){
    .clean-bottom{
        margin-bottom:20px;
    }
    .clean-top{
        margin-top:20px;
    }
}