style.css

html {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: inherit;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    font-weight: normal;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 10px;
    padding: 20px;
}

h1 {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    font-weight: bolder;
    text-transform: capitalize;
}

.container {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    position: relative;
}

canvas {
    border: 10px solid lightgrey;
    margin: 10px;
}

#gameCanvas {
    border-radius: 50%;
    overflow: hidden;
    width: 800px;
    height: 800px;
    background-color: whitesmoke;
}

@media (max-width: 768px) {
    #gameCanvas {
        width: 400px;
        max-width: 98%;
        height: auto;
    }
}

@media (max-width: 768px) {
    button {
        padding: 15px 25px;
        font-size: 18px;
        margin-bottom: 15px;
    }
}

.controls {
    margin-top: 20px;
}

button {
    margin: 0 10px;
    padding: 10px 20px;
}

.rules {
    margin: 16px 0;
    align-items: center;
}

.rules ul {
    margin: 10px 0;
    list-style-type: none;
    line-height: 1.2;
}

#howTo {
    margin-bottom: 20;
}