*{
    margin: 0;
    padding: 0;
}
.lt{
    float: left;
}
.rt{
    float: right;
}
.clear::after{
    clear: both;
    display: block;
    content: "";
}
.top-box{
    width: 100%;
    background-image: url(../phone-imgs/nav.png);
    padding: .1rem;
    box-sizing: border-box;
}
.nav-box{
    display: flex;
}
.nav-box>a{
    width: .7rem;
    margin-left: .1rem;
}
.nav-box>a>img{
    width: 100%;
    display: block;
}
.img-box>img{
    width: 100%;
    display: block;
}
.down-wrap,
.platform-box{
    position: relative; 
    overflow: hidden; 
}
.platform{
    position: absolute;
    bottom: 30%;
}
.down-box{
	width: 100%;
	display: flex;
	display: -webkit-flex;
    justify-content: space-around;
    -webkit-justify-content: space-around;
	position: absolute;
	bottom: 0;
	left: 50%;
    transform: translateX(-50%);
    -webkit-transform: translateX(-50%);
}
.down-box>a{
	width: 30%;
}
.down-box>a>img{
	width: 100%;
	display: block;
}
.platform-box .foot-img{
    width: 92%;
    position: absolute;
    bottom: 14%;
    transform: translateX(-50%);
    margin-left: 50%;
}