.top_img{
    width: 100%;
    height: 300px;
    display: table;
    background-color: rgba(0, 0, 0, 0);
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center center;
}
@media (max-width:700px){
    .top_img{
        height: 250px;
    }
}
@media (max-width:500px){
    .top_img{
        height: 150px;
    }
}
.about_div{
    width: 1200px;
    margin: 20px auto;
}
@media (max-width:1250px){
    .about_div{
        width: 96%;
        margin: 2%;
    }
}
.about_content{
    width: 100%;
}
.about_content img{
    max-width: 100%;
    display: block;
    margin: auto;
}