.nav_up {
    background: url("../images/arrow_up.png") no-repeat scroll 50% 50% rgba(0, 0, 0, 0);
    border: 1px solid #CCCCCC;
    bottom: 10px;
    cursor: pointer;
    height: 20px;
    left: 30px;
    opacity: 0.7;
    padding: 7px;
    position: fixed;
    white-space: nowrap;
    width: 20px;
}
.nav_down {
    background: url("../images/arrow_down.png") no-repeat scroll 50% 50% rgba(0, 0, 0, 0);
    border: 1px solid #CCCCCC;
    bottom: 10px;
    cursor: pointer;
    height: 20px;
    left: 70px;
    opacity: 0.7;
    padding: 7px;
    position: fixed;
    white-space: nowrap;
    width: 20px;
}
#back-top {
    bottom: 0;
    margin-left: -150px;
    position: fixed;
    right: 0;
}
#back-top a {
    display: block;
    font: 11px/100% Arial,Helvetica,sans-serif;
    text-align: center;
    text-decoration: none;
    text-transform: uppercase;
    width: 108px;
}
#back-top a:hover {
    color: #000000;
}
#back-top span {
    background: url("../images/up-arrow.png") no-repeat scroll center center rgba(0, 0, 0, 0);
    border-radius: 15px;
    display: block;
    height: 108px;
    margin-bottom: 7px;
    transition: all 1s ease 0s;
    width: 108px;
}
#back-top a:hover span {
}