@charset "utf-8";
/* CSS Document */





.btn_box{



  margin: 0;
}

#btn_animation .btn {
  display: block;
  position: relative;
  width: 680px;
  height: 200px;

  text-decoration: none;

  color: #fbfbfb;
  text-align: center;
  overflow: hidden;
}

@media ( max-width : 768px ) {
#btn_animation .btn {
  width: 100%;
  height: 100px;
}
}

#btn_animation .btn:hover {
    text-decoration: none;
    color: #fbfbfb;
}

#btn_animation .btn::before {
    position: absolute;
    content: '';
    display: inline-block;
    top: -180px;
    left: 0;
    width: 30px;
    height: 100%;
    background-color: #fbfbfb;
    animation: btn_animation 3.5s ease-in-out infinite;
}

@-webkit-keyframes btn_animation {
    0% { -webkit-transform: scale(0) rotate(45deg); opacity: 0; }
    80% { -webkit-transform: scale(0) rotate(45deg); opacity: 1.5; }
    81% { -webkit-transform: scale(4) rotate(45deg); opacity: 3; }
    100% { -webkit-transform: scale(50) rotate(45deg); opacity: 0; }
}