.grid .tick, .x-axis .tick, .y-axis .tick, .axis-label {
  opacity: 0.5;
  font-size: 11px;
}

/* horizontal grid lines */
.tick line {
  stroke-width: 1px;
  stroke: #777;
}

.y-axis-label {
  text-anchor: middle;
}

/* hide the axis line */
.x-axis path, .y-axis path {
  stroke-width: 0;
}

circle.dot {
  stroke-width: 2px;
  fill-opacity: 0.7;
  stroke-opacity: 0.9;
}

.overlay {
  fill: none;
  pointer-events: all;
}

.overlay-tooltip {
  fill: #777;
  font-size: 12px;
}

.vertical-highlight {
  fill: steelblue;
  opacity: 0.1;
}