JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width">
        <link rel="stylesheet" type="text/css" href="style.css">
        <title>OmkringOs</title>
    </head>
    <body>
            <div id="hallo">
                    <header>
                            <div clas="col-12 col-s-12">
                                    <div class="header">
                                        <h5><span class="highlight">Tordbjørn´s</span> Vinduespoleirng</h5>
                                    </div>
                            </div>
                        </header>
                                        <div>
                                            <div class="col-12 col-s-12 nav_top">
                                                    <div class="dropdown">
                                                    <div class="dropdown" style="float:left;">
                                                        <button class="dropbtn">DropdownMenu</button>
                                                        <div class="dropdown-content" style="left:10;">
                                                          <div class="dropdown-content">
                                                            <a href="index.html">Hjem</a>
                                                            <a href="aboutus.html">Om os</a>
                                                            <a href="contact.html">Kontakt</a>
                                                            <a href="services.html">Services</a>
                                                            <a href="datapolicy.html">Datapolitik</a>
                                                        </div>
                                                    </div>
                                                </div>
                                          </div>
   
                                      </div>
              ...

CSS

* {
          box-sizing: border-box;
        }
       
        .row::after {
          content: "";
          clear: both;
          display: table;
        }
       
        [class*="col-"] {
          float: left;
          padding: 15px;
        }
       
        html {
          font-family: "Lucida Sans", sans-serif, time;
          background-color: #f4f4f4;
        }
       
        .header {
          background-color: #c5e1f3;
          color: #ffffff;
          padding-top: 5px;
          height: 120px;
        }
        .header, h5{
        font-size: 30px;
        text-align: center;
       
        }
       
        .header .highlight, .header, .current a{
          color:#e98f76;
          font-weight: bold;
        }
        .nav_top{
          height: 50px;
          background-color:#c5e1f3;
          margin-top: 0px;
          padding-top: 5px;
          margin-bottom: 0px;
        }
        .showcase{
          min-height: 300px;
          background:url("../Image/chow_img1.jpg") no-repeat ;
          text-align: center;
          color: black
          }
     
      .showcase, h7{
        padding-top: 100px;
          margin-top: 0px;
          font-size: 35px;
          text-align: center;
      }
     
     
      .dropbtn {
        background-color: rgb(11, 126, 233);
        color: white;
        padding: 5px;
        font-size: 13px;
        border: none;
        cursor: pointer;
      }
     
      .dropdown {
        position: relative;
        display: inline-block;
      }
     
      .dropdown-content {
        display: none;
        position: absolute;
        left: 0;
        background-color: #f1f1f1;
        min-width: 160px;
        box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
        z-index: 1;
      }
     
      .dropdown-content a {
        color: black;
        padding: 12px 16px;
        text-decoration: none;
        display: block;
      }
     
      .dropdown-content a:hover {background-color:#ddd;}
     
     ...