/**
 * I was out the other evening looking at Venus with the setting sun and thought, I wonder where all the planets
 * are in relation to each other right now. I knew what an Orrery was, but I'd never built one. So, given my mate
 * Donovan's (@donovanh: http://cssanimation.rocks/) penchant for CSS animation, I thought I'd give it a go 
 * building one in pure CSS.
 * 
 * Many thanks to @aidandore and @iandevlin too for suggestions and improvements
 *
 * Chin up Pluto. You'll always be a planet to me... 
 *
 * Tady: http://tady.me
 * @tadywankenobi
 */

/**
 * Move in a circle without wrapper elements
 * Idea by Aryeh Gregor, simplified by Lea Verou, borrowed by me!
 */

@mixin vp-anim($radius,$pname, $deg: 360deg) {
  @-webkit-keyframes rot-#{$pname} {
    from {
      -webkit-transform: rotate(0deg)
                 translatey(-$radius)
                 rotate(0deg);
    }
    to {
      -webkit-transform: rotate(360deg)
                 translatey(-$radius) 
                 rotate(-$deg);
    }
  }
  @-moz-keyframes rot-#{$pname} {
    from {
      -moz-transform: rotate(0deg)
                 translatey(-$radius)
                 rotate(0deg);
    }
    to {
      -moz-transform: rotate(360deg)
                 translatey(-$radius) 
                 rotate(-$deg);
    }
  }
  @-keyframes rot-#{$pname} {
    from {
      transform: rotate(0deg)
                 translatey(-$radius)
                 rotate(0deg);
    }
    to {
      transform: rotate(360deg)
                 translatey(-$radius) 
                 rotate(-$deg);
    }
  }
}

$baseUnit: 0.1;        // Speed of Orrery. At 1, 1 sec = 1 day
$sunRad: 72px;          // Radius of the sun, added to orbit radii
$rFactor: 2;            // Adding a radius factor so orbit radii are easier to observe
$middleOffset: 800px;

$scale: 0.75;              // Play around with changing this to change the visible motion default: 0.75

$middle: $middleOffset*(1/$scale);

$planets: (
  ('mer',8.8s*$baseUnit,(6px*$rFactor)+$sunRad,1.75px,#888),
  ('ven',22.5s*$baseUnit,(9px*$rFactor)+$sunRad,2.75px,#f5f9be),
  ('ear',36.5s*$baseUnit,(15px*$rFactor)+$sunRad,3.5px,#4b94f9),
  ('mar',68.7s*$baseUnit,(23px*$rFactor)+$sunRad,3px,#dd411a),
  ('jup',433.2s*$baseUnit,(78px*$rFactor)+$sunRad,35px,#eaad3b),
  ('sat',1075.9s*$baseUnit,(145px*$rFactor)+$sunRad,29px,#d6cd93),
  ('ura',3068.7s*$baseUnit,(288px*$rFactor)+$sunRad,13px,#bfeef2),
  ('nep',6019s*$baseUnit,(450px*$rFactor)+$sunRad,12px,#363ed7),
  ('plu',9046.5s*$baseUnit,(587px*$rFactor)+$sunRad,1.5px,#963)
 );

body {
  background-color: #012;
  background-image: url('https://cssanimation.rocks/starwars/images/bg.jpg');
  background-size: 33%;
  background-repeat: repeat;
  min-height: 2700px * $scale;
}


.system {
  position:relative;
  top: 0; left: 0;
  width:100%;
  height:100%;
  -webkit-transform: scale($scale);
  -moz-transform: scale($scale);
  transform: scale($scale);
}

.sun {
  width: $sunRad*2;
  height:$sunRad*2;
  border-radius: $sunRad;
  position:absolute;
  top: $middle;
  left:50%;
  margin: -$sunRad;
  //background-color: yellow;
  background-image: url('http://sdo.gsfc.nasa.gov/assets/img/latest/latest_256_HMIIF.jpg');
  background-size:$sunRad*2;
  background-repeat:no-repeat;
}

@each $planet in $planets {
  $name: nth($planet, 1);
  $orb: nth($planet,2);
  $rad: nth($planet,3);
  $prad: nth($planet,4);
  $col: nth($planet,5);
  
  @include vp-anim($rad,$name);
  
    .#{$name} {
      width: $prad * 2;
      height: $prad*2;
      border-radius:50%;
      background-color:$col;
      position: absolute;
      top: $middle;
      left: 50%;
      margin: -$prad;
      -webkit-animation: rot-#{$name} $orb infinite linear;
      -moz-animation: rot-#{$name} $orb infinite linear;
      animation: rot-#{$name} $orb infinite linear; 
      z-index:200;
    }
  .#{$name}-path {
        $orbitPath: $rad*2;
        width: $orbitPath;
        height: $orbitPath;
        border-radius:50%;
        z-index:100;
        position:absolute;
        top: $middle;
        left:50%;
        margin:-($orbitPath / 2);
        border: solid 1px #444;
      }
}

@include vp-anim(7px,lune);

.lune {
  width:2px;
  height:2px;
  background-color: #fff;
  position:absolute;
  $lunOrb: 2.7s * $baseUnit;
  top: 50%;
  left:50%;
  margin:-1.5px;
  -webkit-animation: rot-lune $lunOrb infinite linear;
  -moz-animation: rot-lune $lunOrb infinite linear;
  animation: rot-lune $lunOrb infinite linear;
}

.mar {
  background-image: repeating-linear-gradient(
    to bottom,
    #fff,
    #fff 1px,
    transparent 1px,
    transparent 5px
  );
}

@include vp-anim(7px,pho);
@include vp-anim(9px,dem);

.pho, .dem {
  width:1px;
  height:1px;
  background-color: #fff;
  position:absolute;
  top: 50%;
  left:50%;
}

.pho {
  $phoOrb: 1.5s * $baseUnit;  // Should be 0.33s but spins like it's having a fit.
  margin:-1px;
  -webkit-animation: rot-pho $phoOrb infinite linear;
  -moz-animation: rot-pho $phoOrb infinite linear;
  animation: rot-pho $phoOrb infinite linear;
}

.dem {
  $demOrb: 2s * $baseUnit;  // Should be 1.25s, spins too fast
  margin:-1px;
  -webkit-animation: rot-dem $demOrb infinite linear;
  -moz-animation: rot-dem $demOrb infinite linear;
  animation: rot-dem $demOrb infinite linear;
}

$jupR: 35px;
.jove {
  width:2px;
  height:2px;
  background-color: #fff;
  position:absolute;
  top: $jupR;
  left:50%;
}


@include vp-anim($jupR + 4px,io);
@include vp-anim($jupR + 6px,eur);
@include vp-anim($jupR + 10px,gan);
@include vp-anim($jupR + 18px,cal);

.io {
  $jioOrb: 2s*$baseUnit;
  -webkit-animation: rot-io $jioOrb infinite linear;
  -moz-animation: rot-io $jioOrb infinite linear;
  animation: rot-io $jioOrb infinite linear;
}

.eur {
  $jeurOrb: 3.5s*$baseUnit;
  -webkit-animation: rot-eur $jeurOrb infinite linear;
  -moz-animation: rot-eur $jeurOrb infinite linear;
  animation: rot-eur $jeurOrb infinite linear;
}

.gan {
  $jganOrb: 7s*$baseUnit;
  -webkit-animation: rot-gan $jganOrb infinite linear;
  -moz-animation: rot-gan $jganOrb infinite linear;
  animation: rot-gan $jganOrb infinite linear;
}

.cal {
  $jcalOrb: 16.5s*$baseUnit;
  -webkit-animation: rot-cal $jcalOrb infinite linear;
  -moz-animation: rot-cal $jcalOrb infinite linear;
  animation: rot-cal $jcalOrb infinite linear;
}

.jup {
  background-image: repeating-linear-gradient(
    6deg,
    #797663 22px,
    #e1dcde 16px,
    #c3a992 30px,
    #e9ece2 30px
  );
}

.spot {
  position:absolute;
  width:16px;height:12px;
  border-radius: 8px / 6px;
  top: $jupR+10;
  left:50%;
  background-color:#bc833b;
  box-shadow: 0px 0px 5px #e1dcde;
  border:solid 1px #e1dcde;
  box-sizing:border-box;
  -moz-box-sizing:border-box;
  -webkit-box-sizing:border-box;
  z-index:300;
  .nep & {
    background-color:darken(#343ec5, 10%);
    border: 0;
    box-shadow: none;
    top: 50%;
    left:45%;
    width: 10px;
    height: 6px;
    margin: -2px;
    border-radius: 5px / 3px;
    border-left:solid 1px #7ed6fe;
  }
}

$satD: 29px * 2;
div[class$="-ring"] {
  border-radius: 50%;
  position:absolute;
  top: 50%;
  left:50%;
  opacity: 0.7;
  $tilt: 45deg;
  -webkit-transform: rotatex($tilt);
  -moz-transform: rotatex($tilt);
  transform: rotatex($tilt);
}

.a-ring {
  $ringD: $satD + 61;
  $ringW: 5px;
  border:solid $ringW #96866f;
  width: $ringD;
  height: $ringD;
  margin: -($ringD / 2) - $ringW;
}
.b-ring {
  $ringD: $satD + 46;
  $ringW: 10px;
  border:solid $ringW #554c3c;
  width: $ringD;
  height: $ringD;
  margin: -($ringD / 2) - $ringW;
}

.c-ring {
  $ringD: $satD + 37;
  $ringW: 9px;
  border:solid $ringW #574f4a;
  width: $ringD;
  height: $ringD;
  margin: -($ringD / 2) - $ringW;
}

.f-ring {
  $ringD: $satD + 75;
  $ringW: 2px;
  border:solid $ringW #908e8d;
  width: $ringD;
  height: $ringD;
  margin: -($ringD / 2) - $ringW;
}

$uraD: 13px * 2;
.e-ring {
  $ringD: $uraD + 50;
  $ringW: 7px;
  border:solid $ringW #908e8d;
  width: $ringD;
  height: $ringD;
  margin: -($ringD / 2) - $ringW;
  $tilt: 0deg;
  $axis: 89deg;
  -webkit-transform: rotatex($tilt) rotatey($axis) !important;
  -moz-transform: rotatex($tilt) rotatey($axis) !important;
  transform: rotatex($tilt) rotatey($axis) !important;
}

.plu, .plu-path {
  top: $middle + 287.4px;
}