5.11: Correction

const pingouin =document.getElementById('pingouin');
const eau      =document.getElementById('eau'     );

document.addEventListener('keydown',function(event){
  let top=parseInt(pingouin.style.top);
  if(event.code ==="ArrowUp"  ){top-=30;}
  if(event.code ==="ArrowDown"){top+=30;}
  if(top<0     ){top=0;}
  if(top>450-60){top=450-60;}
  pingouin.style.top=top+'px';
});