JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li class="class1">AFFECTED</li>
    <li class="class1 class2">NOT</li>
    <li class="class1">NOT</li>
</ul>

<ul>
    <li class="class1 class2">NOT</li>
    <li class="class1">AFFECTED</li>
    <li class="class1">NOT</li>
</ul>

<ul>
    <li>NOT</li>  
    <li class="class1">AFFECTED</li>
    <li class="class1">NOT</li>
</ul>

CSS

li[class="class1"] {
    background-color: red;
}

li[class="class1"] ~ li[class="class1"] {
    background-color: transparent;
}