#page_top{
  width: 90px;
  height: 60px;
  position: fixed;
  right: 0;
  bottom: 0;
  opacity: 0.8;
  border: 3px solid #3f98ef;
  border-radius: 15px;
  background-color:#fff;
}
#page_top a{
  position: relative;
  display: block;
  width: 90px;
  height: 60px;
  text-decoration: none;
}
#page_top a::before{
  font-family: 'Font Awesome 5 Free';
  font-weight: 900;
  content: '\f062';
  font-size: 25px;
  color: #3f98ef;
  position: absolute;
  width: 25px;
  height: 25px;
  top: -25px;
  bottom: 0;
  right: 0;
  left: 0;
  margin: auto;
  text-align: center;
}
#page_top a::after{
  content: 'PAGE TOP';
  font-size: 13px;
  color: #3f98ef;
  position: absolute;
  top: 38px;
  bottom: 0;
  right: 0;
  left: 0;
  margin: auto;
  text-align: center;
}