JSFiddle - React, Tailwind, and code Playground

HTML

<table class="tablebox">
      <tr class="head">
        <td class="cell10">Icon</td>

        <td class="cell10">Status</td>

        <td class="cell50">
          <table class="group">
            <tr class="colGroup">
              <td>
                <table class="box yellow">
                  <tr class="color">
                    <td class="leftbox"></td>
                    <td class="rightbox">6</td>
                  </tr>
                </table>
              </td>

              <td>
                <table class="box red">
                  <tr class="color">
                    <td class="leftbox"></td>

                    <td class="rightbox">12</td>
                  </tr>
                </table>
              </td>

              <td>
                <table class="box green">
                  <tr class="color">
                    <td class="leftbox"></td>
                    <td class="rightbox">7</td>
                  </tr>
                </table>
              </td>

              <td>
                <table class="box blue">
                  <tr class="color blue">
                    <td class="leftbox"></td>

                    <td class="rightbox">7</td>
                  </tr>
                </table>
              </td>
            </tr>
          </table>
        </td>

        <td class="cell30">Ma&#223;nahmen</td>
      </tr>
        <tr class="sub">
          <td colspan="4">
          <table>
            <tr class="colGroup">
              <td>
                <table class="box yellow">
                  <tr class="color yellow">
                    <td class="leftbox"></td>

                    <td class="rightbox">6</td>
                  </tr>
                </table>
              </td>

              <td>
                <table class="box red">
                  <tr class="color red">
                    <td class="leftbox"></td>

                    <td class="rightbox">12</td>
                  </tr>
               ...

CSS

/*______ff88cc________________ffbbee__________________________________________________________________________*/
/*_____ Genutzte Schriftfamilien _________________________________________________________________*/
	body, p, h1, h2, h3, h4, h5, h6, ul, ol, li, div, td, th { font-family: Arial,Helvetica,helv,Sans; }
	tt                                          { font-family: Courier; }

/*________________________________________________________________________________________________*/
/*_____ Abstände und Ausrichtungen _______________________________________________________________*/

/* ____ Standard-Elemente ____________________________________________________________________*/
 body                { margin-left: 25pt; max-width:800px;}
 p, ul, ol, li, div, tt   { margin-top: 2pt;  margin-bottom: 2pt;}
 p, ul             { padding-bottom: 2pt;}
 h1, .toc      { margin-top: 15pt; margin-bottom: 0pt; margin-left: -15pt; }
 h2                  { margin-top: 15pt; margin-bottom: 0pt; margin-left: -15pt; }
 h3                  { margin-top: 10pt; margin-bottom: 0pt; margin-left: -10pt; }
 h4, h5, h6            { margin-top: 10pt; margin-bottom: 0pt; }
 th                  { margin-top: 2pt;  margin-bottom: 2pt; text-align: left; vertical-align: top; }
 td                  { margin-top: 2pt;  margin-bottom: 2pt; vertical-align:top; }

 table {border:1px solid; border-collapse:collapse;margin-top:3px; margin-bottom:3px;}
 td,th {border:1px solid; padding-left:2px; padding-right:2px; padding-top:1px; padding-bottom:1px;}
 .table_noborder, .table_noborder td, .table_noborder th {border-style: none;}

/*________________________________________________________________________________________________*/
/*_____ Schriftgrößen und -ausgestaltungen _______________________________________________________*/

/* ____ Standard-Elemente ____________________________________________________________________*/
 body, p, ul, ol, li, div, td, address, nobr, i   { font-size: 10pt; }
 h1,...

JavaScript

$(function() {
  $("tr.sub").hide();
  $(".tablebox tr.head").click(function(){
      $(this).next("tr").fadeToggle(500);
  });
});