html, body {
  margin: 0;
  padding: 0;
}
canvas {
  display: block;
}

 .container {
        width: 150px;
        height: 150px;
        position: relative;
        margin: 30px;
      }
      .box {
        width: 100%;
        height: 100%;
        position: absolute;
        top: 0;
        left: 0;
        opacity: 0.7;
      }
.overlay {
  z-index: 9;
  margin: 30px;  
}