.toTopH {
position:fixed;
right:4%;
bottom:4%;
width:56px;
height:56px;
background:#666;
border-radius:56px;
text-align:center;
transition:500ms;
line-height:56px;
display:none;
font-size:16px;
z-index:999999999;
color:#fff;
cursor:pointer;
}
.aip-back-top i {
color:#fff;
}