body{
    margin: 0;
    background-color: black;
    overflow: hidden;
}

.center{
    text-align: center;
}

.circle{
    margin-left: 50%;
    margin-top: 25%;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background-color: red;
}
.circle:hover{
    background-color: darkred;
}

.score{
    color: white;
    font-size: xx-large;
    font-family: Arial;
}

.timer{
    color: white;
    font-size: xx-large;
    font-family: Arial;
}

.high_score{
    color: white;
    font-size: xx-large;
    font-family: Arial;
}

.btn{
    width: 100px;
    height: 40px;
    margin: 5px;
    margin-top: 15px;
    margin-bottom: 15px;
    border-radius:10%;
    font-weight: bolder;
    font-family: Arial;
    font-size: medium;
}
.btn:hover{
    background-color: lightcoral;
}