JSFiddle - React, Tailwind, and code Playground

HTML

<div class="code-box">
    <span class="code-header">Sample code</span>
    <ol class="code-sample">
        <li class="code-line"><code>while true do</code></li>
        <li class="code-line"><code>    wait()</code></li>
        <li class="code-line"><code>end</code></li>
    </ol>
</div>

CSS

.code-box {
    border: 1px solid #808080;
    border-radius: 10px;
    overflow: hidden;
    padding: 4px;
}
.code-box .code-header{
    display: block;
    padding-bottom: 5px;
    text-align: center;
}

.code-box .code-sample{
    list-style-type: decimal;
    list-style-type: decimal-leading-zero;
    font-family: monospace;
    
    padding-left: 8ex;
    background-color: #808080;
    border-radius: 5px;
    
    overflow: hidden;
}
.code-box .code-line code{
    display: inline-block;
    white-space: pre-wrap;
    margin-left: -3ex;
    padding-left: 1ex;
    border-left: 1ex solid #808080;
    padding-right: 1ex;
    width: 100%;
    background-color: #e0e0e0;
}

.code-line:nth-child(even) code{
    background-color: #f0f0f0;
}