JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block">
    <div class="basics">
        Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
        <span class="switch">+/-</span>
    </div>
    <div class="details">        
        <div class="pinned">
        At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.<br />
        Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.
        </div>
    </div>
</div>

<div class="block">
    <div class="basics">
        Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
        <span class="switch">+/-</span>
    </div>
    <div class="details">
        <div class="pinned">
        At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.<br />
        Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.<br />
        At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.
        </div>
    </div>
 </div>

<div class="block">
    <div class="basics">
        Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
       ...

CSS

div.block {
		 position: relative;
		 overflow: hidden;
		 border: 1px solid #333;
         border-bottom: 0px;
		 line-height: 20px;         
         background-color: #fff;
	 }
         div.block:last-child {
             border-bottom: 1px solid #333;
         }
	 div.basics {
		 position:relative;
		 background-color: #fff;
		 z-index: 2;
         padding: 2px 4px;
	 }
	 div.details {
		 border-top: 1px solid #333;
		 position: relative;
		 background-color: #99F;
		 z-index: 1;
		 height: auto;
         display: none;
	 }
        div.pinned {
            position: absolute;
            bottom: 0px;
            left: 0px;
            height: auto;
        }
     span.switch {
         float: right;
         cursor: pointer;
         font-size: 20px;
         font-weight: bold;
     }

JavaScript

(function(a){a.fn.addBack=a.fn.addBack||a.fn.andSelf;
a.fn.extend({actual:function(b,l){if(!this[b]){throw'$.actual => The jQuery method "'+b+'" you called does not exist';}var f={absolute:false,clone:false,includeMargin:false};
var i=a.extend(f,l);var e=this.eq(0);var h,j;if(i.clone===true){h=function(){var m="position: absolute !important; top: -1000 !important; ";e=e.clone().attr("style",m).appendTo("body");
};j=function(){e.remove();};}else{var g=[];var d="";var c;h=function(){c=e.parents().addBack().filter(":hidden");d+="visibility: hidden !important; display: block !important; ";
if(i.absolute===true){d+="position: absolute !important; ";}c.each(function(){var m=a(this);var n=m.attr("style");g.push(n);m.attr("style",n?n+";"+d:d);
});};j=function(){c.each(function(m){var o=a(this);var n=g[m];if(n===undefined){o.removeAttr("style");}else{o.attr("style",n);}});};}h();var k=/(outer)/.test(b)?e[b](i.includeMargin):e[b]();
j();return k;}});})(jQuery);

$(document).ready(function(){
    $('.details').each(function(){
        $(this).height($(this).find('.pinned').actual('height'));
    });
          $('.switch').click(function(event) {                            
			  $(this).closest('.block').find('.details').slideToggle('slow');
		  });
});

$(window).resize(function() {
    $('.details').each(function(){
        $(this).height($(this).find('.pinned').actual('height'));
    });
});