#page_top{
    position: fixed;
    right: 30px;
    bottom: 10px;
    opacity: 1;
    z-index: 30000;
}
a:link {
     color: #fff;
}
a:visited {
    color: #fff;
}

.pc { 
	display: block !important;
}
.sp {
	display: none !important;
}
 
@media only screen and (max-width: 768px) {
    .pc {
	display: none !important;
	}
    .sp {
	display: block !important;
	}
}
a.btn_back {
    display: block;
    text-align: center;
    vertical-align: middle;
    text-decoration: none;
    width: 120px;
    margin: auto;
    padding: 1rem 4rem;
    font-weight: bold;
    border: 2px solid #ffffff;
    color: #ffffff;
    border-radius: 100vh;
    transition: 0.5s;
}
a.btn_back:hover {
    color: #fff;
    background: #a57d4b;
}