JSFiddle - React, Tailwind, and code Playground
HTML
<div class="a">
<div class="b">Hello</div>
</div>
<div class="c">
<div class="b">World</div>
</div>
CSS
div:not(.a) .b {
color: red;
}
<div class="a">
<div class="b">Hello</div>
</div>
<div class="c">
<div class="b">World</div>
</div>
div:not(.a) .b {
color: red;
}