body {
    background-color: #DBDFFD;
}

h1 {
    color: aliceblue;
}
#container {
    margin: auto;
    justify-content: center;
    text-align: center;
    width: 90%;
    background-color: #413F42;
    padding:  0px 40px 60px;
}

#screen {
    width: 98%;
    height: 30px;
    font-size: 24px;
    margin-bottom: 10px;
    border: 2px solid black;
    margin-bottom: 20px;
    margin: 0 px;
    background-color: #677d6c;
}

#container>#keyboard {
    display: grid;
    grid-template-columns: repeat(4, 24%);
    grid-gap: 5px;
    justify-content: center;
    text-align: center;
    width: 100%;
    
}

#container>#keyboard>button {
    border: 1px solid black;
    border-radius: 5px;
    cursor: pointer;
    font-size: 20px;
    height: 55px;
    background-color: #F9F9F9;
    font-weight: bold;
    font-style:inherit;
}

#container>#keyboard>.num {
    background-color: #F9F9F9;
    color: #1B2430;
}
#container>#keyboard>.equal {
    background-color: #A64B2A;
    color: #1B2430;
}

#container>#keyboard>.char {
    background-color: #2c2f4d;
    color: #F9F9F9;
}

@media only screen and (min-device-width: 660px)  {
    #container>#keyboard {
        grid-gap: 10px;
    }

    #container>#keyboard>button {
        font-size: 30px;
        height: 80px;
    }
    #screen {
        width: 98%;
        height: 60px;
        font-size: 30px;
    }
}
@media only screen and (max-device-width: 660px)  {
    
    #container>#keyboard {
    
        grid-gap: 8px;
    }

    #container>#keyboard>button {
        font-size: 24px;
        height: 70px;
    }
    #screen {
        width: 98%;
        height: 35px;
        font-size: 25px;
    }
}

@media only screen and (max-device-width: 320px)  {
    
    #container>#keyboard>button {
        font-size: 20px;
        height: 70px;
    }
   
}