body {
    background-image: linear-gradient(180deg, rgba(0,0,0,0.9) 0, rgba(0,0,0,0.7) 100%), url(../img/fb2-2.jpg);
    background-size: cover;
    background-position: center;
    height: 100vh;
    width: 100%;
}
.logo {
    margin-top: 30px;
    width: 300px;
    height: auto;
}