body {
    background: lime;
}

.grid {
width: 400px;
height: 400px;
border: 5px solid lime ;
margin: 0 auto;
display: flex;
flex-wrap: wrap;
background-color: rgb(100, 100, 255);
}

.grid div {
    width: 40px;
    height: 40px;
    /*border:1px black solid;
    box-sizing:border-box*/
}

.snake {
    background: yellow;
}

.apple {
    background: red;
    border-radius: 20px;
}

.popup {
    /*background: rgb(0, 235, 0);*/
    width: 100%;
    /*height: 30px;*/
    top: 100px;
    left: 100px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: xx-large;
    margin: 10px;
}

.text-center {
    text-align: center;
}