style.css

.ticks {
     font-size: 10px;
}

 * {
     font-family: Arial;
}
 .track, .track-inset, .track-overlay {
     stroke-linecap: round;
}
 .track {
     stroke: #000;
     stroke-opacity: 0.3;
     stroke-width: 10px;
}
 .track-inset {
     stroke: #ddd;
     stroke-width: 8px;
}
 .track-overlay {
     pointer-events: stroke;
     stroke-width: 50px;
     stroke: transparent;
     cursor: crosshair;
}
 .handle {
     fill: #fff;
     stroke: #000;
     stroke-opacity: 0.5;
     stroke-width: 1.25px;
}
 .country {
     stroke: #CCC;
     vector-effect: non-scaling-stroke;
}
 div.tooltip {
     position: absolute;
     text-align: center;
     padding: 2px;
     font: 12px sans-serif;
     background: white;
     border-width: 1px;
     border-color: black;
     pointer-events: none;
}
 svg {
     display: block;
     margin-left: auto;
     margin-right: auto;
}
 input {
     margin-left: 12px;
     margin-right: 2px;
}
 #controls {
     text-align: center;
}