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                .wrap {
  position: relative;
.square {
  top: 0;
  left: 0;
  position: absolute;
  background-color: orange;
  width: 50px;
  height: 50px;


                const secondPerFrame = 16.66666666;//1フレーム何ミリ秒にするか
const FPS = 1000 / secondPerFrame;
//そして、毎秒何フレームを表示するか: 約60フレーム = 60FPS

let animation = ($el) => {
  let leftPos = 0;//箱のポジション値を保存
  let goalVal = 1000;//最終的にいてほしいポジション
  let duration = 1000;//適当に決めたトータル秒
  let elapsedTime = 0;//経過した時間(秒)を保存
  let tick = () => {
    if(elapsedTime >= duration) {//1秒たったら終わり
      leftPos = goalVal;
    let elapsedTimeRate = elapsedTime / duration;
    //経過時間割合(進捗率) 〜 どれくらい時間が経過したか?
    let valueChangeRate = elapsedTimeRate;
    //値の変化割合 〜 とりあえず経過時間割合と同じに
    leftPos = goalVal * valueChangeRate;
    $el.css('left', leftPos);
    elapsedTime += secondPerFrame;
    setTimeout(tick, secondPerFrame);

  $('.square').on('click', function(){