* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
    font-size: 16px;
}

#canvas {
    position: absolute;
    display: block;
    width: 100%;
    height: 100%;
}

#main-menu {
    position: absolute;
    margin-top: -100px;
    margin-left: -100px;
    left: 50%;
    top: 50%;
    width: 200px;
    height: 200px;
}

#main-menu label {
    display: inline-block;
    margin: 12px 0;
    width: 150px;
}

#main-menu input {
    margin: 0;
}

#main-menu input[type=number] {
    max-width: 50px;
}

#main-menu input[type=submit] {
    width: 100%;
}

#quick-play {
    width: 100%;
}

#or {
    margin-top: 10px;
    text-align: center;
    font-size: 12px;
    color: gray;
}