*{
    padding:0;
    margin:0;
    box-sizing: border-box;
}

header{
    background-color:rgba(0,0,0,0.6);
    background-size:cover;
    background-repeat: no-repeat;
    background-position: center;
    height:100vh;
    min-height:500px;
}

#section-1{
    min-height:500px;
}