#header{
    margin:0 auto;
}

.content img{
    width:100vw;
    max-width:100%;
    height:auto;
}

.pc_img{
    display:block;
}

.sp_img{
    display:none;
}

@media screen and (min-width:641px){
    #header{
        width:1024px;
    }
}

@media screen and (max-width:640px){
    .pc_img{
        display:none;
    }
    
    .sp_img{
        display:block;
    }
}