JSFiddle - React, Tailwind, and code Playground

HTML

<div class="Container">
	<div class="Header">
		<p>PHP: include("header.php");
		<p>The Header div height is not fixed (But he can be if you want it to)</p>
		<p>This Layout has been tested on: IE10, IE9, IE8, FireFox, Chrome, Safari, Opera. using Pure CSS 2.1 only</p>
	</div>
	<div class="Content">
		<div class="Wrapper">
			<div class="RightContent">
				<p>PHP: include("content.php");</p>
				<p>In content.php $_REQUEST['id'] o.i.d. ophalen en hier showen</p>
				<p>You can fix the width of this content.</p>
				<p>if you wont, his width will stretch just as it needs to.</p>
			</div>
			<div class="LeftContent">
				<p>PHP: include("menu.php");</p>
				<p><a href="#">index.php?id=1</a></p>
				<p><a href="#">index.php?id=2</a></p>
				<p><a href="#">index.php?id=3</a></p>
				<p><a href="#">index.php?id=4</a></p>
				<p><a href="#">index.php?id=5</a></p>
				<p><a href="#">index.php?id=6</a></p>
				<p><a href="#">index.php?id=7</a></p>
				<p><a href="#">index.php?id=8</a></p>
				<p><a href="#">index.php?id=9</a></p>
				<p><a href="#">index.php?id=10</a></p>
				<p><a href="#">index.php?id=11</a></p>
				<p><a href="#">index.php?id=12</a></p>
				<p><a href="#">index.php?id=13</a></p>
				<p><a href="#">index.php?id=14</a></p>
				<p><a href="#">index.php?id=15</a></p>
				<p><a href="#">index.php?id=16</a></p>
				<p><a href="#">index.php?id=17</a></p>
				<p><a href="#">index.php?id=18</a></p>
				<p><a href="#">index.php?id=19</a></p>
				<p><a href="#">index.php?id=20</a></p>
				<p><a href="#">index.php?id=21</a></p>
				<p><a href="#">index.php?id=22</a></p>
				<p><a href="#">index.php?id=23</a></p>
				<p><a href="#">index.php?id=24</a></p>
				<p><a href="#">index.php?id=25</a></p>
				<p><a href="#">index.php?id=26</a></p>
				<p><a href="#">index.php?id=27</a></p>
				<p><a href="#">index.php?id=28</a></p>
				<p><a href="#">index.php?id=29</a></p>
				<p><a href="#">index.php?id=30</a></p>
				<p><a href="#">index.php?id=31</a></p>
				<p><a...

CSS

*
{
    margin: 0;
    padding: 0;
}

html, body, .Container
{
    height: 100%;
}

    .Container:before
    {
        content: '';
        height: 100%;
        float: left;
    }

.Header
{
    margin-bottom: 10px;
    background-color: #6ea364;
}
.Content
{
    position: relative;
    z-index: 1;
}
    .Content:after
    {
        content: '';
        clear: both;
        display: block;
    }

.Wrapper
{
    position: absolute;
    width: 100%;
    height: 100%;
}
    .Wrapper > div
    {
        height: 100%;
    }

.LeftContent
{
    background-color: lightgrey;
    overflow: auto;
}

.RightContent
{
    background-color: orange;
    float: right;
    margin-left: 10px;
}