* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    height: 80vh;

    display: flex;
    justify-content: center;
    align-items: center;
}

canvas {
    max-width: 640px;
    max-height: 406px;
    border-left: 2px solid #bdc3c7;
    border-right: 2px solid #bdc3c7;

    display: block;
}

button {
    color: #34495e;
    background-color: #ecf0f1;
    padding: 8px 15px;
    border: 2px solid #bdc3c7;
    border-radius: 5px;
    cursor: pointer;
    box-shadow: 0px 0px 5px 0px lightgray;

    position: absolute;
    top: 100px;
    left: 100px;

    transition: all .15s;
}

button:hover {
    color: white;
    background-color: #95a5a6;
    border: 2px solid #7f8c8d;
}