JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">    
    <div id="panel">
        <div id="panel1" class="panelcell"></div>
        <div id="panel2" class="panelcell"></div>
        <div id="panel3" class="panelcell"></div>
        <div id="panel4" class="panelcell"></div>
        <div class="spacer" style="clear: both;"></div>
    </div>
</div>

CSS

#wrapper{
    width: 1280px;
}
#panel{
	width:100%;
}

#panel .panelcell{
	width: 318.75px;
	height: 213px;
	float: left;
	border-right: 1px solid white;
}

.panelcell {
    background-color: gray;
}

#panel1{
    border-right: 1px solid white;
}