body,
html {
    margin: 0;
    padding: 0;
    height: 100%;
    width: 100%;
}

.fullscreen-bg {
    background-image: url('yapimasamasinda.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 100vh;
}

@media only screen and (max-width: 1024px){
    .fullscreen-bg {
        background-size: contain;
    }
}