#BackToTop {
	bottom:0px;
	right:0px;
	position:fixed;
	opacity:0.5;
	transition:all .5s;
	cursor:pointer;
	transform:scale(.7,.7);
	transform-origin:right bottom;
	z-index:10;
}
#BackToTop:hover {
	opacity:1;
}

/*手机端底部菜单*/
@media (min-width: 600px) {
    .nav-shouji {
        display: none !important;
    }
}
.nav-shouji{
--background: #eee;
--main: #eee;
            display: flex;
            position: fixed;
            bottom:0;
            z-index:1;
            height: 55px;
            width: 100%;
            background: var(--background);
            flex-shrink: 0;
            font-size: 14px;
filter:alpha(opacity=80); /*仅在ie中支持*/
opacity:0.8; /*不支持ie*/
left:0;
        }
        .nav-shouji .nav-item {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            width: 100%;
            color: var(--main);
        }       

        .nav-shouji .nav-item img {
            width: 26px;
            height: 26px;
            overflow: hidden;
       }

.cont { 
    display: none; 
    position: fixed; 
    top: 40%;
    left: 50%;
    margin-top: -10%;
    margin-left: -35%; 
    width: 70%; 
    height: 50%; 
    border: 10px solid #ddd; 
    background-color: lightblue; 
    color: #000000;
    z-index:100; 
    overflow: auto; 
}