.auto_img {

    width: auto;
    height: auto;
    max-width: 100%;
    max-height: 100%;
    display: block;

}
.center{
    text-align: center;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.centertop{
    text-align: center;
    display: block;
    margin-top: 0;
    margin-left: auto;
    margin-right: auto;
    top: 0;
}

.main{
    #border: solid;
    #border-width: 5px;
    #border-color: white;
    color: white;
}

.container{
    width: 50%;
    height: 50%;
    float: left;
}