*{margin: 0; padding: 0;}

body{
    font-family: Verdana;
    font-size: 30px;
}

header{
    background: url("clouds.jpg") center;
    width: 100hw;
    height: 100vh;
    background-size: cover;
    display: flex;
    align-items: center;
    justify-content: center;
}

header h1{
    text-align: center;
    background-color: rgba(100, 100, 100, 0.8);
    color: #ffffff;
    padding: 10px;
    border-radius: 10px;
}

/* ----------  big screen  ----------*/
@media (max-width: 1600px) and (orientation: landscape){
    header h1{
        font-size: 48px;
    }
}
@media (max-width: 1200px) and (orientation: portrait){
    header h1{
        font-size: 40px;
    }
}


/* ----------  large screen  ----------*/
@media (max-width: 1280px) and (orientation: landscape){
    header h1{
        font-size: 40px;
    }
}
@media (max-width: 820px) and (orientation: portrait){
    header h1{
        font-size: 32px;
    }
}


/* ----------  medium screen  ----------*/
@media (max-width: 960px) and (orientation: landscape){
    header h1{
        font-size: 28px;
    }
}
@media (max-width: 550px) and (orientation: portrait){
    header h1{
        font-size: 22px;
    }
}

/*-----  small screen  -----*/
@media (max-width: 641px) and (orientation: landscape){
    header h1{
        font-size: 24px;
    }
}
@media (max-width: 400px) and (orientation: portrait){
    header h1{
        font-size: 18px;
    }
}