.btn-style{
    min-width: 150px;
    margin-right: 10px;
    margin-top: 20px;
}

body{
    padding-top: 70px;
}

.menu {
    position: absolute;
    top: 0px;
    left: 0px;
    width: 100%;
    height: 30px;
    padding: 10px;
    color: white;
    background-color: black;
}

.img-center{
    margin-top: 30px;
    margin-left: auto;
    margin-right: auto;
}