/* ここはコピーしなくてOK　*/
.container {
  @import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@700&display=swap');
  font-family: 'Noto Sans JP', sans-serif;
  text-align: center;
  padding-top: 40px;
}

/* ここから下がボタンのCSS　*/
.btn-rotation {
  display: inline-block;
  text-decoration: none;
  color: #FFF;
  font-weight: 700;
  background-color: #65A04D;
  width: 200px;
  text-align: center;
  padding: 16px;
  position: relative;
  opacity: 1 !important;
  transition: all 0.4s;
  line-height: 1.2;
  border-radius: 4px;
  border: 2px solid #65A04D;
}
.btn-rotation:hover {
  transform: rotateX(180deg);
  background-color: #FFF;
  color: #65A04D;
}
.btn-rotation:hover span {
  transform: rotateX(180deg);
}
.btn-rotation:hover span:nth-child(1) {
  visibility: hidden;
  height: 0;
  width: 0;
  opacity: 0;
}
.btn-rotation:hover span:nth-child(2) {
  visibility: visible;
  width: 100%;
  height: inherit;
  opacity: 1;
}
.btn-rotation span {
  display: block;
  transition: opacity 0.3s 0.2s;
  width: 100%;
  height: inherit;
}
.btn-rotation span:nth-child(2) {
  visibility: hidden;
  height: 0;
  width: 0;
  opacity: 0;
}