JSFiddle - React, Tailwind, and code Playground

HTML

<div class="conteudo">
    <p>Blablabla, conteúdo aqui.</p>
</div>

CSS

.conteudo {
    width:300px;
    height:200px;
    position:relative;
}
.conteudo * {
    position:relative;
    z-index:2;
    color:white;
}
.conteudo:before {
    content:'';
    width:100%;
    height:100%;
    z-index:1;
    position:absolute;
    top:0;
    left:0;
    background:url(http://www.placecage.com/300/200);
    opacity:0.5
}
body {
    background:linear-gradient(blue, white, blue, white, blue, white);
}