html {
  min-height:100%;
  background: 
   linear-gradient(rgba(255,0,0,1) 0%, rgba(255,154,0,1) 10%, rgba(208,222,33,1) 20%, rgba(79,220,74,1) 30%, rgba(63,218,216,1) 40%, rgba(47,201,226,1) 50%, rgba(28,127,238,1) 60%, rgba(95,21,242,1) 70%, rgba(186,12,248,1) 80%, rgba(251,7,217,1) 90%, rgba(255,0,0,1) 100%) 
   0 0/100% 200%;
   animation: a 2s linear infinite;
}

@keyframes a {
  to {background-position:0 -200%}
}


@keyframes move {
  0%   {left:0px; top:0px;}
  35%  {left:70vw; top:0px;}
  40%  {left:70vw; top:30vh;}
  75%  {left:0px; top:30vh;}
  100% {left:0px; top:0px;}
}

#bird {
  width: 300px;
  height:auto;
  animation: move 4s linear infinite;
  position:relative;
}
#birdball{
  border-radius:1000px;
}