JSFiddle - React, Tailwind, and code Playground

HTML

<aside id="sidebar">
    <ul>
        <li>
            <a href="#" id="itemLinea1">Linea 1</a>
        </li>
        <li>
            <a href="#">Linea 1</a>
        </li>
        <li>
            <a href="#">Linea 1</a>
        </li>
        <li>
            <a href="#">Linea 1</a>
        </li>
    </ul>
</aside>

CSS

aside#sidebar ul {
    margin-top: 15px;
    width: 100%;
    height: 200px;
    background: transparent;
}
aside#sidebar ul li {
    font-size: 14px;
    list-style-type: none;
    margin-bottom: 5px;
    //border: 3px solid white;
    

}
aside#sidebar ul li a {
    display: block;
    padding: 5px;
    color: white;
    border-left: 10px solid white;
    
    border-radius: 12px;
    -webkit-border-radius: 12px;
    -moz-border-radius: 12px;
        background-color: #000;

}
aside#sidebar #itemLinea1 {
    //border-color: #DE9E26;
    behavior: url(PIE.htc);
    background: url(data:image/svg+xml;base64,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);
    background: -moz-linear-gradient(top, rgba(252,234,187,1) 0%, rgba(252,205,77,0.75) 50%, rgba(248,181,0,0.75) 51%, rgba(251,223,147,0.5) 100%);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(252,234,187,1)), color-stop(50%,rgba(252,205,77,0.75)), color-stop(51%,rgba(248,181,0,0.75)), color-stop(100%,rgba(251,223,147,0.5)));
    background: -webkit-linear-gradient(top, rgba(252,234,187,1) 0%,rgba(252,205,77,0.75) 50%,rgba(248,181,0,0.75) 51%,rgba(251,223,147,0.5) 100%);
    background: -o-linear-gradient(top,...