.hidden{
    display:none;
    overflow:hidden;
}
body.dark{
    background-color: #333333;
    color:#fff;
    overflow: hidden;
}
#e:active{
    color: #fff;
}
#number-container{
    margin-top: 55px;
}
header{
    margin-left:500px;
    font-size: 1.2rem;
    font-weight: bold;
}
#game{
    display:flex;
    justify-content: center;
}
#buts{
    margin-top: 260px;
    margin-left: 20px;
    height:120px;
    width: 50px;
}
.b{
    padding:10px;
    font-weight: bold;
    font-size: 1.7rem;
    border-radius: 10px;
    margin-top: 20px;
    width:25px;
    height:25px;
    color:white;
    text-align: center;
    cursor:pointer;
}
.b:hover{
    background-color:#3d3c3c;
}
.b:active{
    background-color: #696868;
}
.digits{
    border:1px solid black;
    border-radius: 20%;
    width:45px;
    height:45px;
    font-size: 30pt;
    margin-left: 50px;
    margin-top:5px;
    margin-bottom: 5px;
    text-align: center;
    cursor:pointer;
}
.digits:hover{
    background:#3d3c3c;
}
.digits:active{
    background:#696868;
}
.active{
    background:#696868;
}
#board{
    padding-top:10px;
    margin-top:10px;
    display:flex;
    flex-wrap: wrap;
    justify-content: center;
    align-content: flex-start;
    width:600px;
    height:600px;
}
.tile{
    border:1px solid black;
    width:60px;
    height: 60px;
    text-align: center;
    margin:0px;
    font-size: 40pt;
    justify-content: center;
    background:#ffffffa2;
    color:black;
    cursor:pointer;
}
.tile:hover{
    background:rgb(155, 208, 226);
}
.selected{
    background-color: lightblue;
}
.rightBorder{
    border-right: 4px solid black;
}
.bottomBorder{
    border-bottom: 4px solid black;
}
@media screen and (max-width:500px){
    header{
        margin-left:130px;
    }
    #game{
        margin-top: 20px;
    }
    #board{
        height: 250px;
        width:250px;
        padding-top:0;
        margin-top:50px;
        display:flex;
        flex-wrap: wrap;
        justify-content: center;
        align-content: flex-start;
    }
    #buts{
        margin-top: 60px;
        margin-left: 5px;
    }
    #number-container{
        margin-left:0px;
        padding-left:5px;
        width:40px;
        margin-top: 5px;
    }
    .tile{
        margin:0;
        width:25px;
        height:25px;
        font-size:1.6rem;
    }
    .digits{
        width:30px;
        height:30px;
        font-size:1.6rem;
        margin-top: 0;
        margin-left: 0px;
    }
}