.banner {
    position: relative;
    width: 100%;
    height: 500px;
    box-sizing: border-box;
    z-index: 3;
    color: #fff;
    background:#314d67 url(../images/banner-index4.png) center no-repeat;
    background-size: cover;
    padding-top: 220px;
}
.banner .bannertext {
    text-align: center;
    font-size: 48px;
    font-weight: 600;
    margin: 0 auto;
}
.Rearth{
    position: absolute;
    left: calc(50% - 150px);
    top:100px;
    z-index: -99;
}
.Rearth img{
    animation: newsearth 40s infinite;
}
@keyframes newsearth{
    0% {transform: rotate(0);}
    100% {transform: rotate(1turn);}
}

@media screen and (max-width: 768px) {
    .banner{
        
    width: 100%;
    overflow: hidden;
    box-sizing: border-box;
    margin-top: 49px;
    border-bottom: 1px solid #ccc;
    text-align: center;
    padding-bottom: 40px;
    height: 380px;
    text-align: center;
    }
    .Rearth{
        top: 50px;
    }
    .banner .bannertext {
    margin-top: -50px;
}
}