canvas, body, html {
  height : 100%;
  width : 100%;
  overflow: hidden;
  padding : 0;
  margin : 0;
  z-index: 0;
} 

body {
   background: #a7cfdf; /* Old browsers */
   background: -webkit-linear-gradient(bottom left, #a7cfdf 0%, #23538a 100%);
   background: -moz-linear-gradient(bottom left, #a7cfdf 0%, #23538a 100%);
   background: -o-linear-gradient(bottom left, #a7cfdf 0%, #23538a 100%);
   background: linear-gradient(to top right, #a7cfdf 0%, #23538a 100%);
   z-index: -1;
}