JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.1/css/all.min.css">
<div id="oModal" class="oModal">
  <div align="right">
    <p><a href="#fermer"><i class="fa fa-times orange btn"></i></a></p>
    <div class="cv_header">
      <h1>Mais qui est-ce ?</h1>
    </div>

CSS

#oModal {
  position:fixed;
  inset:5%;
  background:blue
}