*
{
   margin:0;
   padding:0;
   box-sizing: border-box; 
}
body
{
  overflow: hidden;
}
section
{
   display:flex;
   justify-content: center;
   align-items: center;
   height: 100vh;
   background: #034071;
}
section .runway
{
   position: relative;
   width: 400px;
   height: 100vh;
   background: #1378bc;
   border-left: 20px solid rgba(0,0,0,0.25);
   border-right: 20px solid rgba(0,0,0,0.25);
   transition: transform 1s;
   transition-delay: 1s;
   transform-origin: top; 
}
section:active .runway
{
  transform: scaleX(0.7) scaleY(0);
  transition-delay: 0s;
  transform-origin: bottom;
}
/*plane fly on click left+hold & land when you release the left click*/
section .runway::before
{
    content:"";
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%);
    width: 25px;
    height: 100%;
    background: repeating-linear-gradient(transparent 0%,transparent 50%,#fff 50%,#fff 100%);
    background-size:20px 320px;
    animation: animateRunway 0.5s linear infinite;
}
/* add effect on left click on hold */
section:active.runway::before
{
  animation: animateRunway 0.25s linear infinite;
}  


@keyframes animateRunway
{
  0%
  {
    background-position-y: 0px;
  }
  100%
  {
    background-position-y: 640px;
  }  
}
.plane
{
  position:absolute;
  bottom: 100px;
  max-width: 250px;
  pointer-events: none;
  filter: drop-shadow(10px 10px 0 rgba(0,0,0,0.5));
  transition:  5s;
}
section:active .plane
{
  max-width: 500px;
  filter: drop-shadow(200px 200px 0 rgba(0,0,0,0));
}
.clouds
{
  position:absolute;
  left:0;
  width: 100%;
  height: 100%;
  z-index: 10000;
  pointer-events: none;
  opacity: 0;
  transition: opacity 2s;
  transition-delay: 0s; 
}
section:active .clouds
{
  opacity: 1;
  transition-delay: 1s;
}
.clouds img
{
  position: absolute;
  left: 0;
  width: 800px; 
  animation: animateClouds 4s linear infinite;
  animation-delay: calc(-1.5s*var(--i));
}
.clouds2
{
  right: 0;
  transform: rotate(180deg); 
}
.clouds2 img
{
  animation: animateClouds2 4s linear infinite;
  animation-delay: calc(-1.5s*var(--i));    
}
@keyframes animateClouds
{
  0%
  {
    transform: translateY(-100%);
  }
  100%
  {
    transform: translateY(100%);
  }
}
@keyframes animateClouds2
{
  0%
  {
    transform: translateY(100%);
  }
  100%
  {
    transform: translateY(-100%);
  }
}