The style declarations contained within this page:
.cl1:first-line strong {color: red;} /* element mismatch */
.cl2em {color: red;} /* missing space on purpose */
.cl2+.cl3 {color: green;} /* no space around + combinator */
.cl3 + .cl4 {color: green;} /* extra space around + combinator */
[cl1] The emphasized text in the first line of this element should NOT be red, but the same color as the text in the element.
[cl2] The emphasized text in this element should NOT be red, but the same color as the text in the element.
[cl3] The text in this element should be green.
[cl4] The text in this element should be green.