.my-desc{
    width:95%;
    min-width:930px;
    margin:0 auto;
    margin-top:20px;
}
.my-content{
    width:95%;
    min-width:950px;
    background-color:red;
} 
canvas.snow {
      display: block;
      position: fixed;
      top:0;
      left:0;
      height: 100%;
      width: 100%;
      z-index:-1;
    }