/* Comments in code. */
.comment {
    color: purple;
}

/* Highlighted changes in code. */
.highlight {
    background-color: mistyrose;
}

/* Manual input. */
.in {
    color: darkgreen;
}

/* Program output. */
.out {
    color: darkblue;
    font-style: italic;
}

/* Error output. */
.err {
    color: darkred;
    font-style: italic;
    font-weight: bold;
}

/* Explanatory call-out boxes. */
div.box {
    background-color: lightgray;
}

/* Challenge questions. */
div.challenges {}

/* Key points in summary. */
div.keypoints {}

/* Main lesson. */
div.lesson {}

/* Learning objectives. */
div.objectives {}

/* Continuation paragraph. */
p.continue {}