JSFiddle - React, Tailwind, and code Playground

HTML

<div id="außenbox">
<div class="gebiet">
  <div id="arbe">
    <div class="arbe-content">
      <div class="header">
        <h2>LAAAAAAAAnger TEXXXXXXTTTTT</h2></div>
      <div class="copy">
        <ul>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
        <a href="#">Schließen</a> </div>
    </div>
    <div class="overlay"></div>
  </div>
  <a href="#arbe" class="arbe">LAAAAAAAAnger TEXXXXXXTTTTT</a>
</div>
<div class="gebiet">
  <div id="arbe">
    <div class="arbe-content">
      <div class="header">
        <h2>LAAAAAAAAnger TEXXXXXXTTTTT</h2></div>
      <div class="copy">
        <ul>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
        <a href="#">Schließen</a> </div>
    </div>
    <div class="overlay"></div>
  </div>
  <a href="#arbe" class="arbe">LAAAAAAAAnger TEXXXXXXTTTTT</a>
</div>
<div class="gebiet">
  <div id="arbe">
    <div class="arbe-content">
      <div class="header">
        <h2>LAAAAAAAAnger TEXXXXXXTTTTT</h2></div>
      <div class="copy">
        <ul>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
        <a href="#">Schließen</a> </div>
    </div>
    <div class="overlay"></div>
  </div>
  <a href="#arbe" class="arbe">LAAAAAAAAnger TEXXXXXXTTTTT</a>
</div>
<div class="gebiet">
  <div id="arbe">
    <div class="arbe-content">
      <div class="header">
        <h2>LAAAAAAAAnger TEXXXXXXTTTTT</h2></div>
      <div class="copy">
        <ul>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
        <a href="#">Schließen</a> </div>
    </div>
    <div class="overlay"></div>
  </div>
  <a href="#arbe" class="arbe">LAAAAAAAAnger TEXXXXXXTTTTT</a>
</div>
<div class="gebiet">
  <div id="arbe">
   ...

CSS

#außenbox { display: flex; justify-content:space-around; flex-wrap: wrap;}
.gebiet {flex: 0 1 15%; margin: 12px}

#arbe {
  left: 50%;
  margin: -250px 0 0 -32%;
  opacity: 0;
  position: absolute;
  top: -50%;
  visibility: hidden;
  width: 65%;
  box-shadow: 0 3px 7px rgba(0,0,0,.25);
  box-sizing: border-box;
  transition: all .4s ease-in-out;
  -moz-transition: all .4s ease-in-out;
  -webkit-transition: all .4s ease-in-out
}

#arbe:target {
  opacity: 1;
  top: 50%;
  visibility: visible
}

/* Modal styles */
#arbe .header, #arbe .footer {
  border-bottom: 1px solid #e60000;
  border-radius: 5px 5px 0 0
}

#arbe .footer {
  border: none;
  border-top: 1px solid #e7e7e7;
  border-radius: 0 0 5px 5px
}

#arbe h2 {
  margin: 0;
  color: #fff
}

#arbe .btn { float: right }

/*Textfenster */
#arbe .copy, #arbe .header, #arbe .footer {
  padding: 10px;
  color: #454A52;
}

.arbe-content {
  background: #26292D;
  position: relative;
  z-index: 20;
  border-radius: 5px;
  color: #fff
}

#arbe .copy, { background: white}

#arbe .overlay,{
  background-color: #000;
  background: rgba(0,0,0,.8);
  height: 100%;
  left: 0;
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 10
}