.about-img-box{
    padding: 0 0 0px 20px;
    margin: 0 0 10px;
}
.about-img-box>img{
    width: 100%;
}
.about-img-certificate>img{
    float:left;
    max-height: 220px;
    -webkit-box-shadow: 3px 3px 10px 0px rgba(0,0,0,0.5);
    -moz-box-shadow: 3px 3px 10px 0px rgba(0,0,0,0.5);
    box-shadow: 3px 3px 10px 0px rgba(0,0,0,0.5);
}
.about-img-certificate>img:first-child{
    margin: 0 40px 0 0;
}
@media  screen and (max-width: 1199px){
    .about-img-certificate>img{
        max-height: 180px;
    }
}
@media  screen and (max-width: 991px){
    .about-img-box{
        text-align: center;
        margin: 50px 0;
    }
    .about-img-box>img{
        width: 320px;
    }
    .about-img-certificate{
        margin: 0 auto;
        display: inline-block;
        width: 100%;
        text-align: center;
    }
    .about-img-certificate>img{
        width: 30%;
        max-height: initial;
        float: none;
        display: inline-block;
    }
}
@media  screen and (max-width: 350px){
    .about-img-box{
        padding: 0;
    }
    .about-img-box>img{
        width: 260px;
    }
    .about-img-certificate>img:first-child{
        margin: 0 0 30px 0;
    }
    .about-img-certificate>img{
        width: 60%;
    }
}