Untitled

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
<style id="jsbin-css">
#canvas {
  width: 300px;
  height: 300px;
  background-color: ivory;
  margin: 0 auto;
  box-shadow: 15px 15px 10px gray;
}
#first-row {
  height: 75%;
  width: 100%;
}
#big-rectangle {
  height: 100%;
  width: 75%;
}
.red{
  background-color: red;
}
.right{
  float: right;
}
.black {
  background-color: black;
}
#first-divider {
  height: 100%;
  width: 3%;
}
#first-column {
  height: 100%;
  width: 22%;
}
#second-divider {
  height: 3%;
  width: 100%;
}
#first-medium-rectangle {
  height: 48.5%;
  width: 100%;
}
#second-medium-rectangle {
  height: 48.5%;
  width: 100%;
}
#second-row {
  height: 3%;
  width: 100%;
}
</style>
</head>
<body>
 <div id="canvas">
   <div id="first-row">
    <div id="big-rectangle" class="red right"></div>
    <div id="first-divider" class="black right"></div>
   </div>
   <div id="first-column" class="right">
    <div id="first-medium-rectangle"></div>
    <div id="second-divider" class="black"></div>
    <div id="second-medium-rectangle"></div>
   </div>
   <div id="second-row" class="black"></div>
 </div>


<script id="jsbin-source-css" type="text/css">#canvas {
  width: 300px;
  height: 300px;
  background-color: ivory;
  margin: 0 auto;
  box-shadow: 15px 15px 10px gray;
}
#first-row {
  height: 75%;
  width: 100%;
}
#big-rectangle {
  height: 100%;
  width: 75%;
}
.red{
  background-color: red;
}
.right{
  float: right;
}
.black {
  background-color: black;
}
#first-divider {
  height: 100%;
  width: 3%;
}
#first-column {
  height: 100%;
  width: 22%;
}
#second-divider {
  height: 3%;
  width: 100%;
}
#first-medium-rectangle {
  height: 48.5%;
  width: 100%;
}
#second-medium-rectangle {
  height: 48.5%;
  width: 100%;
}
#second-row {
  height: 3%;
  width: 100%;
}</script>
</body>
</html>