*{
    text-align: center;
    font-family:'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
}

.square{
    width: 150px;
    height: 150px;
    background-color: blanchedalmond;
    border: 1px solid gray;
    display: inline-block;
}

.o{
    position: relative;
}

.o:after{
    position: absolute;
    content:"\1F6E1";
    font-size: 50px;
    line-height: 150px;
    left: 0px;
    right: 0px;
    top: 0px;
    bottom: 0px;
}

.x{
    position: relative;
}

.x:after{
    position: absolute;
    content:"\2694";
    font-size: 50px;
    line-height: 150px;
    left: 0px;
    right: 0px;
    top: 0px;
    bottom: 0px;
}

button {
    margin-top: 20px;
    font-size: larger;
}

button{
    padding: 15px;
    border-radius: 15px;
    border: none;
    background-color: rgb(81, 81, 189);
    color: blanchedalmond;
}