JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div class="flex-container">
        <div class="flex-item">1</div>
        <div class="flex-item">100</div>
        <div class="flex-item">10,000</div>
        <div class="flex-item">1,000,000</div>
        <div class="flex-item">100,000,000</div>
        <div class="flex-item">10,000,000,000</div>
        <div class="flex-item">1,000,000,000,000</div>
    </div>
    <div class="flex-container">
        <div class="flex-item">100</div>
        <div class="flex-item">100</div>
        <div class="flex-item">100</div>
        <div class="flex-item">100</div>
        <div class="flex-item">100</div>
        <div class="flex-item">100</div>
        <div class="flex-item">100</div>
    </div>
</body>

CSS

.flex-container {
    padding: 0;
    margin: 0;
    list-style: none;
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-flex-flow: row;
    justify-content: space-around;
    height: 50px;
    line-height:30px;
}

.flex-item {
    background: tomato;
    margin: 10px 5px;
    color: white;
    font-weight: bold;
    font-size: 1.5em;
    text-align: center;
    flex-basis: 100%;
    overflow: hidden;
}