body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #a8c0ff;
}

.game {
    position: relative;
    width: 400px;
    height: 200px;
    border: 2px solid #333;
    background-color: #d8e4ff;
}

.ground {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 30px;
    background-color: #8f5914;
}

.mario {
    position: absolute;
    bottom: 30px;
    left: 50px;
    width: 30px;
    height: 30px;
    background-color: red;
}