html,
body {
overflow: hidden;
width: 100%;
height: 100%;
margin: 0px;
}
#chart {
margin: 0px;
align-content: middle;
position: absolute;
width: 100%;
}
#dropdown {
position: absolute;
top: 0px; /* compensate the borders */
left: 0px;
border: 0px;
-webkit-transform: translateY(+100%);
-moz-transform: translateY(+100%);
opacity: 0.25;
}
#dropdown:hover {
opacity: 1.0;
border: 0px;
}