JSFiddle - React, Tailwind, and code Playground

HTML

<body>
        <div class="flex-container">
            <div class="item-1">1</div>
            <div class="item-2">2</div>
            <div class="item-3">3</div>
            <div class="item-4">4</div>
            <div class="item-5">5</div>
            <div class="item-6">6</div>
        </div>
    </body>

CSS

* {
    box-sizing: border-box;
    font-size: 1.5rem;
}

html {
    background: #b3b3b3;
    padding: 5px;
}

body {
    background: #b3b3b3;
    padding: 5px;
    margin: 0;
  }
  
.flex-container {
    height: 500px;
    background: white;
    padding: 10px;
    border: 5px solid black;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content:space-evenly;
    align-items: flex-start;
    align-content: center;

  }

.item-1 {
    background: #ff7300;
    color: white;
    padding: 10px;
    border: 5px solid black;
    margin: 10px;
}

.item-2 {
    background: #ff9640;
    color: white;
    padding: 10px;
    border: 5px solid black;
    margin: 10px;
}

.item-3 {
    background: #ff9640;
    color: white;
    padding: 10px;
    border: 5px solid black;
    margin: 10px;

}

.item-4 {
    background: #f5c096;
    color: white;
    padding: 10px;
    border: 5px solid black;
    margin: 10px;

}

.item-5 {
    background: #d3c0b1;
    color: white;
    padding: 10px;
    border: 5px solid black;
    margin: 10px;
}

.item-6 {
    background: #d3c0b1;
    color: white;
    padding: 10px;
    border: 5px solid black;
    margin: 10px;
}