body{
background-image: url("cool-background.png");
background-size: cover;
font-family: Arial, Helvetica, sans-serif;
text-align: center;

}


h1{
    margin-top: 10%;
}

hr{
width: 500px;
height: 3px;
margin-top: 2%;
background-color: black;
}

#board{
width: 450px;
height: 450px;
margin: 0 auto;
display: flex;
flex-wrap: wrap; 

}

.tile{
    width: 147px;
    height: 147px;
    font-size: 150px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.horizontal-line{
    border-bottom:3px solid black ;
}

.vertical-line{
    border-right:3px solid black ;
}

.winner{
    background-color: lightgray;
    color: red;
}