.line_btn {
    position: absolute;
    bottom: 50px;
    right: 50px;
    z-index: 10;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 300px;
    height: 200px;
    animation: floatUpDown 2s ease-in-out infinite;
    transition: transform 0.3s;
    line-height: 0%;
}

.line_btn :hover {
  transform: scale(1.1);
}

.line_btn_txt {
  width: 100%;
  height: 50%;
  padding-top : 40px;
  padding-bottom: 20px;
  margin-bottom : 0;
  text-align: center;
  color: white;
  text-shadow: 2px 2px 4px black;
  z-index: 10;
  font-size: 30px;
  font-weight: bold;
}

.line_btn_img {
  width: auto;
  height: 69.95px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.line_btn_img img {
  width: auto;
  height: 69.95px;
  border-radius: 5%;
}

@media screen and (max-width: 600px) {
  .line_btn {
    justify-content: center;
    align-items: center;
  }

  .line_btn_txt {
    font-size: 20px;
    padding-top: 20px;
  }
  
  .line_btn_img img {
    width: 200px;
  }
}

@keyframes floatUpDown {
  0% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
  100% {
    transform: translateY(0);
  }
}