我正在寻找仅在有 2 个班级时才会发生的事情。
例如:
.positive{
color:#46a546;
}
.positive:after{
content: "\25b2";
}
.negative{
color:#F00;
}
.arrow:after{
content: "\25bc";
}
<span class="positive"> hi </span>
<span class="positiveArrow"> hi </span>
<span class="negativeArrow"> hi </span> //what i have
<span class="positive arrow"> hi </span>
<span class="negative arrow"> hi </span> // what i want