JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <div id="child"></div>
    <div id="child"></div>
    <div id="child"></div>
    <div id="child"></div>
    <div style="clear:both"></div>
</div>

<div id="parent2">
    <div id="child"></div>
    <div id="child"></div>
    <div id="child"></div>
    <div id="child"></div>
    <div style="clear:both"></div>
</div>
<div id="parent3">
    <div id="child"></div>
    <div id="child"></div>
    <div id="child"></div>
    <div id="child"></div>
    <div style="clear:both"></div>
</div>

CSS

#parent, #parent2, #parent3 {
    background: #0f0;
    float: left;
    margin-bottom: 10px;
}
#parent2 {
    width: 660px;
}
#parent3 {
    width: 440px;
}
#child {
    background: #f22;
    float: left;
    height: 150px;
    margin: 10px;
    width: 200px;    
}