.lesson {
    position: absolute;
    z-index: 10001;
    min-width: 200px;
    padding: 8px;
    border-radius: 4px;
    color: white;
    background-color: rgba(0, 0, 0, 0.8);
}

.lesson button {
    border-radius: 4px;
    background-color: white;
    color: black;
    padding: 4px;
    margin-top: 4px;
    margin-bottom: 4px;
}

.lesson:after {
    border: solid transparent;
	  content: " ";
	  height: 0;
	  width: 0;
	  position: absolute;
	  pointer-events: none;
	  border-color: rgba(213, 60, 60, 0);;
	  border-width: 10px;
	  margin-top: -10px;
}

.lesson.top:after {
    top: 100%;
	  left: 50%;
    border-top-color: rgba(0, 0, 0, 0.8);
    margin-top: 0;
    margin-left: -10px;
}

.lesson.bottom:after {
    bottom: 100%;
	  left: calc(50% - 10px);
    border-bottom-color: rgba(0, 0, 0, 0.8);
}

.lesson.right:after {
	  right: 100%;
	  top: 50%;
	  border-right-color: rgba(0, 0, 0, 0.8);
}

.lesson.left:after {
	  left: 100%;
	  top: 50%;
	  border-left-color: rgba(0, 0, 0, 0.8);
}

.lesson.bottom-left {
    border-top-right-radius: 0;
}

.lesson.bottom-left:after {
	  left: 100%;
	  top: 10px;
	  border-left-color: rgba(0, 0, 0, 0.8);
    border-top-color: rgba(0, 0, 0, 0.8);
}

.lesson.bottom-right {
    border-top-left-radius: 0;
}

.lesson.bottom-right:after {
	  right: 100%;
	  top: 10px;
	  border-right-color: rgba(0, 0, 0, 0.8);
    border-top-color: rgba(0, 0, 0, 0.8);
}

.lesson.top-left {
    border-bottom-right-radius: 0;
}

.lesson.top-left:after {
	  left: 100%;
	  bottom: 0px;
	  border-left-color: rgba(0, 0, 0, 0.8);
    border-bottom-color: rgba(0, 0, 0, 0.8);
}

.lesson.top-right {
    border-bottom-left-radius: 0;
}

.lesson.top-right:after {
	  right: 100%;
	  bottom: 0px;
	  border-right-color: rgba(0, 0, 0, 0.8);
    border-bottom-color: rgba(0, 0, 0, 0.8);
}

/* tutorial context */

.context-container {
    position: fixed;
    left: 0;
    bottom: 0;
    width: 100%;
    box-sizing: border-box;
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 2em;
    z-index: 10000;
}

.tutorial-description {
    width: 40%;
    display: inline-block;
}

.tutorial-description h2 {
    margin-top: 0;
}

.tutorial-completion {
    text-align: center;
}

.lesson-navigation {
    width: 20%;
    display: inline-block;
    text-align: center;
    line-height: 2em;
    font-size: 3em;
    vertical-align: bottom;
}

.lesson-navigation span {
    vertical-align: middle;
}

.context-controls a, .lesson-navigation a {
    cursor: pointer;
    color: hotpink;
}

.lesson-navigation a.disabled {
    color: gray;
    pointer-events: none;
}

.context-controls {
    position: absolute;
    top: 12px;
    right: 12px;
    line-height: 1em;
    font-size: 1.5em;
    text-align: right;
}

.tutorial-progress {
    width: 100%;
    height: 10px;
    border: 1px solid lightgreen;
    text-align: center;
}

.tutorial-progress-bar {
    position: relative;
    background-color: lightgreen;
    transition: width 250ms ease-in-out;
    height: 100%;
}

.tutorial-progress-steps {
    display: table;
    width: 100%;
    table-layout: fixed;
    margin-top: -17px;
    margin-bottom: 10px;
}

.progress-step {
    display: table-cell;
    width: 2%;
    text-align: center;
}

.progress-step > div {
    position: relative;
    margin: 0 auto;
    width: 20px;
    height: 20px;
    border-radius: 20px;
}

.progress-step.complete > div {
    border: 1px solid lightgreen;
    background-color: darkgreen;
}

.progress-step.incomplete > div {
    border: 1px solid lightgreen;
    background-color: rgb(255,64,129);
}

/* help mode */

.help-outline {
    position: absolute;
    box-shadow: 0 0 12px 12px rgba(255, 215, 0, 0.3);
    outline: 2px solid gold;
    z-index: 10000;
}