#aboutus{
    padding-top: 150px;
}
#contents{
    margin-top: 50px;
}

.main{
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}
.main img{
    width: 350px;
}
#contents img{
    max-width: 100%;
}
.main h4{
    position: absolute;
    top: 50%;
    left: 50%;
    color: white;
    transform: translate(-50%,-50%);
}

@media only screen and (max-width: 768px) {
    .main img{
        width: 250px;
    }
    .main h4{
        font-size: 18px;
    }
}