.lesson-art { color: var(--lesson-teal); }
.lesson-plot { display: block; width: 100%; height: auto; }
.lesson-plot path, .lesson-plot circle, .lesson-plot line, .lesson-plot polygon {
  vector-effect: non-scaling-stroke; stroke-linecap: round; stroke-linejoin: round;
}
.lesson-plot .plot-main { fill: none; stroke: currentColor; stroke-width: 3; }
.lesson-plot .plot-secondary { color: var(--lesson-teal-secondary); stroke: currentColor; }
.lesson-plot .plot-main.plot-secondary { stroke-dasharray: 6 5; }
.lesson-plot .plot-axis { fill: none; stroke: currentColor; stroke-width: 1; opacity: .22; }
.lesson-plot .plot-guide { fill: none; stroke: currentColor; stroke-width: 1; opacity: .55; }
.lesson-plot .plot-dashed { stroke-dasharray: 5 5; }
.lesson-plot .plot-point { fill: currentColor; stroke: none; }
.lesson-plot .plot-ring { fill: none; stroke: currentColor; stroke-width: 3; }
.lesson-plot .plot-area { fill: currentColor; fill-opacity: .09; stroke: none; }