JSFiddle - React, Tailwind, and code Playground

HTML

<section class="container">
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x234/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x645/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x343/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x643/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x323/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x234/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x564/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x465/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x400/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x456/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x232/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x543/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x433/444444" width="100%">
    </article>
    <article class="thumbnail_small">
        <img src="http://dummyimage.com/424x376/444444" width="100%">
    </article>
</section>

CSS

.container { width: 864px; 
   display: block;
   display: -webkit-flex;
   display: -moz-flex;
   display: flex;
   -webkit-align-items: left;
   -webkit-moz-items: left;
   align-items: left;
   -webkit-justify-content: left;
   -moz-justify-content: left;
   justify-content: left;
   -webkit-flex-direction: row;
   -moz-flex-direction: row;
   flex-direction: row;
   -webkit-flex-wrap: wrap;
   -moz-flex-wrap: wrap;
   flex-wrap: wrap;
   -webkit-flex-flow: row wrap;
   -moz-flex-flow: row wrap;
   flex-flow: row wrap;
   -webkit-align-content: flex-end;
   -moz-align-content: flex-end;
   align-content: flex-end;

.thumbnail_small { margin:0 8px 8px 0;   display: inline-block;
    display: box; }