style.css

*{
    padding :0;
    margin:0;
    font-family:'Geneva',sans-serif;
}
.background{
    height:900px;
    background-image:url("play.jpg");
    background-position: center;
    background-size:cover;
    background-repeat: no-repeat;
}
.BOX{
    width:400px;
    height:200px;
    padding:10px;
    border:5px solid white;
    margin: auto;
    background: black;
}
.heading1{
    color:black;
    font-size: 25px;
    text-align: center;
    margin-top: 0em;
    margin-bottom: 0em;
    background-color:khaki;
}
.heading2{
    color :khaki;
    font-size:25px;
    text-align:center;
}
.heading3{
    color :khaki;
    font-size:25px;
    text-align:center;
    animation: glow 1s ease-in-out infinite alternate;
}
@-webkit-keyframes glow {
  from {
    text-shadow: 0 0 10px #fff, 0 0 20px #fff, 0 0 30px #e60073, 0 0 40px #e60073, 0 0 50px #e60073, 0 0 60px #e60073, 0 0 70px #e60073;
  }

  to {
    text-shadow: 0 0 20px #fff, 0 0 30px #ff4da6, 0 0 40px #ff4da6, 0 0 50px #ff4da6, 0 0 60px #ff4da6, 0 0 70px #ff4da6, 0 0 80px #ff4da6;
  }
}
#X{
    background-color:#4CAF50;
    border: none;
    color:white;
    text-align: center;
    cursor:pointer;
    font-size: 16px;
    padding: 10px 32px;
    border-radius: 8px;
    margin-left:40px;
}
#O{
    background-color:#4CAF50;
    border: none;
    color:white;
    text-align: center;
    cursor:pointer;
    font-size: 16px;
    padding: 10px 32px;
    border-radius: 8px;
    margin-left:55px;
}
.play{
    background-color:#4CAF50;
    border: none;
    color:white;
    text-align: center;
    cursor:pointer;
    font-size: 16px;
    padding: 10px 32px;
    border-radius: 8px;
    margin-left:150px;
}