body
{
    position: fixed; 
    overflow-y: scroll;
    width: 100%;
}

div.tab {
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

/* Style the buttons inside the tab */
div.tab button {
    background-color: inherit;
    float: left;
    border: none;
    outline: none;
    cursor: pointer;
    padding: 14px 16px;
    transition: 0.3s;
}

/* Change background color of buttons on hover */
div.tab button:hover {
    background-color: #ddd;
}

/* Create an active/current tablink class */
div.tab button.active {
    background-color: #ccc;
}

canvas {
    border:1px solid #d3d3d3;
    background-color: #000000;
}