body {
  font-family: 'Helvetica', sans-serif;
  background-color: #eee;
  margin: 0;
  padding: 40px;
  text-align: center;
}

h1 {
  font-size: 2.8em;
  color: #333;
  margin-bottom: 10px;
}

.description {
  font-size: 1.1em;
  color: #777;
  margin-bottom: 40px;
}

.canvas {
  width: 600px;
  height: 400px;
  margin: 0 auto;
  background-image: url('https://www.transparenttextures.com/patterns/cream-paper.png');
  background-size: cover;
  border: 3px solid #aaa;
  position: relative;
}

.shape {
  position: absolute;
  opacity: 0.95;
}

.square {
  width: 100px;
  height: 100px;
}

.circle {
  width: 80px;
  height: 80px;
  border-radius: 50%;
}

.red { background-color: #e74c3c; top: 40px; left: 50px; }
.yellow { background-color: #f1c40f; top: 180px; left: 80px; }
.blue { background-color: #3498db; top: 100px; left: 220px; }
.green { background-color: #2ecc71; top: 240px; left: 300px; }

.triangle {
  width: 0;
  height: 0;
  border-left: 60px solid transparent;
  border-right: 60px solid transparent;
  border-bottom: 100px solid #9b59b6;
  top: 40px;
  left: 420px;
}

.bar {
  width: 160px;
  height: 30px;
  background-color: #34495e;
  top: 300px;
  left: 200px;
}