JSFiddle - React, Tailwind, and code Playground

HTML

<div class="mb bo">
    <div class="mb">
        <div class="mb">
            <p class="foo">foo</p>
        </div>
    </div>
</div>
<div class="bo">
    <p class="bar">bar</p>
</div>

CSS

.bo + .bo {
    margin-top: 10px; 
}

.foo,
.bar {
    margin: 0;
    padding: 10px;
    color: white;
    background-color: grey;
    border: 1px solid blue;
}

.bo {
    border: 1px solid red;
}