.background {
    background: url("../img/background.jpg");
    background-size: cover;
    background-repeat: no-repeat;
    position: fixed;
    left:0;
    top: 0;
    width: 100%;
    height: 100%;
    background-position: center center;
}
.box {
    position: absolute;
    top: 400px;
    left: 50%;
    width: 300px;
    background: white;
    text-align: center;
    margin-left: -150px;
}
button {
    color: #30282a;
    background: none;
    border: none;
    box-shadow: none;
    font-weight: bold;
    margin: 0 0 20px;
    text-transform: uppercase;
}
@media(max-width: 767px){
    .box{
        top:unset;
        bottom: 100px
    }
}