.site-explain{
    width: 40vw;
    margin: 0 auto 7vw;
}
.site-explain img{
    width: 100%;
}
@media screen and (max-width:1025px){
    .site-explain{
        width: 60vw;
    }
}
@media screen and (max-width:600px){
    .site-explain{
        width: 80vw;
    }
}