JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div class="content_panel active">
        <ul class="unstyled items_board">
            <li class="item_header">First</li>
            <li class="has_details item">one</li>
            <li class="has_details item">two</li>
            <li class="has_details item">three</li>
            <li class="has_details item">four</li>
            <li class="has_details item">five</li>
            <li class="has_details item">six</li>
            <li class="item_header">Second</li>
            <li class="has_details item">one</li>
            <li class="has_details item">two</li>
            <li class="has_details item">three</li>
            <li class="has_details item">four</li>
            <li class="has_details item">five</li>
            <li class="has_details item">six</li>
        </ul>
    </div>
</body>

CSS

body {
    background: #fcfcfc;
    font-family:"Open Sans", "Helvetica Neue", Helvetica, sans-serif;
}
.content_panel .active {
    display: inherit;
}
.unstyled {
    margin-left: 0;
    list-style: none;
    /* border:1px solid #e5edec; */
}
ul {
    display: block;
    -webkit-margin-before: 1em;
    -webkit-margin-after: 1em;
    -webkit-margin-start: 0px;
    -webkit-margin-end: 0px;
    -webkit-padding-start: 40px;
    margin: 0 0 10px 25px;
    list-style: none;
    padding-left: 0;
    margin-left: 0;
}
li {
    line-height: 20px;
    float: left;
}
ul > .unstyled {
    margin-left: 0;
    list-style: none;
}
.items_board {
    padding: 4px;
    min-height: 500px;
}
.item_header {
    background: transparent;
    width: 100%;
    margin-right: 0;
    padding: 0;
    margin-bottom: 20px;
    margin-top: 42px;
    cursor: auto;
    border: none;
    -moz-box-shadow: none;
    -webkit-box-shadow: none;
    box-shadow: none;
}
.item_header:first-child {
    margin-top: 8px;
}
.items_board > .item {
    height: 300px;
    margin: 0 -1px -1px 0;
    display: inline-block;
    position: relative;
    vertical-align: top;
    width: 205px;
    background: #fff;
    text-align: left;
    color: #5a5a5a;
    font-weight: 400;
    border: 1px solid #e5edec;
}
.has_details {
    cursor: pointer;
}