style.css

* {
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif, serif;
    box-sizing: border-box;

}

body {
    margin: 0px;
    width: 99%;
    display: flex;
    height: 97vh;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    background-color: rgba(240, 187, 25, 0.633);
}

.choose {
    display: flex;
    flex-direction: column;
    margin-top: 20px;
}

.frame {
    display: flex;
    flex-direction: row;
}

.contentBox {
    margin-top: 0px;
    display: flex;
    flex-direction: column;
    width: 90%;
    align-items: center;
}

.currentPlayer {
    padding-bottom: 1rem;
    display: flex;
    justify-content: space-around;
    width: 500px;
}

.form-control {
    border-radius: 12px;
    background-color: rgb(255, 235, 205);
    padding: 5px;
}

.choose label {
    margin-bottom: 0.5rem;
}

#selectGame {
    font-family: 'Times New Roman', Times, serif;
}

#winner {
    margin-bottom: 0;
}

#startButton {
    border: 1px solid black;
    background-color: rgb(255, 235, 205);
    border-radius: 12px;
    width: 200px;
    position: absolute;
    z-index: 2;
    padding: 5px;
}

#playAgain {
    border: 1px solid black;
    background-color: rgb(255, 235, 205);
    border-radius: 12px;
    width: 200px;
    position: relative;
    padding: 5px;
}

.boardContainer {
    height: 70%;
    width: 850px;
    display: flex;
    justify-content: center;
    align-content: center;
    background: url("images/frame.png") repeat 0 0;
    background-size: 885px 885px;
    background-position: absolute;
    background-position-y: -128px;
    padding-bottom: 100px;
    margin: 0;
}

.board {
    margin-top: 150px;
    margin-left: 30px;
    width: 360px;
    height: 360px;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    z-index: 1;
    position: relative;
}

.cell {
    flex: 0 0 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    font-size: 50px;
}

.cell:nth-child(3n+2) {
    border-left: 5px solid black;
    border-right: 5px solid black;
}

.cell:nth-child(n+4):nth-child(-n+6) {
    border-top: 5px solid black;
    border-bottom: 5px solid black;
}