style.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
section{
    height: 100vh;
    position: relative;
    text-align: center;
}
html{
    font-size: 62.5%;
}

h1,h2,h3{
    font-size: 4rem;
}

.game-section{
    width: 50rem;
    height: 50rem;
    position:absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%,-50%);
    background-color: rgb(218, 112, 209);
}

.row{
    height: 33.3%;
}
.col{
    border: 2px solid rgb(0, 0, 0);
    width: 32.95%;
    height: 100%;
    display: inline-block;
    position:static;
    position: relative;
}

.col h1{
    top: 50%;
    left: 50%;
    position: absolute;
    transform: translate(-50%,-50%)
}

.popUp{
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    background-color: rgba(241, 162, 15, 0.849);
    height: 100vh;
    width: 100vw;
}

.popUpBox{
    height: 15rem;
    width: 30rem;
    background-color: white;
    position: absolute;
    top: 10%;
    left: 50%;
    transform: translate(-50%,-50%);
    padding: 2.5rem 0;
    border-radius: 1rem;
}
.popUp button{
    padding: 0.5em 1em;
    outline: none;
    background-color: rgb(0, 118, 148);
    border: none;
    border-radius: 5rem;
    font-size: 2rem;
    box-shadow: 0px 0px 15px rgba(0, 0, 0, 0.548);
}
.popUp button:hover{
    background-color: rgba(0, 118, 148, 0.904);
    color: white;
    box-shadow: 0px 0px 15px rgba(0, 0, 0, 0.733);
}
.popUp h1{
    margin-bottom: 0.5rem;
}