.cd-top {
  display: inline-block;
  height: 60px;
  width: 60px;
  position: fixed;
  bottom: 50px;
  left: 20px;
  -webkit-box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
          box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
  /* image replacement properties */
  overflow: hidden;
  text-indent: 100%;
  white-space: nowrap;
  background: rgba(188, 15, 15, 0.8) url(../img/cd-top-arrow.svg) no-repeat center 50%;
  visibility: hidden;
  opacity: 0;
  -webkit-transition: opacity .3s 0s, visibility 0s .3s, background-color .3s 0s;
  transition: opacity .3s 0s, visibility 0s .3s, background-color .3s 0s;
}

.cd-top.cd-top--show,
.cd-top.cd-top--fade-out,
.cd-top:hover {
  -webkit-transition: opacity .3s 0s, visibility 0s 0s, background-color .3s 0s;
  transition: opacity .3s 0s, visibility 0s 0s, background-color .3s 0s;
}

.cd-top.cd-top--show {
  /* the button becomes visible */
  visibility: visible;
  opacity: 1;
}

.cd-top.cd-top--fade-out {
  /* if the user keeps scrolling down, the button is out of focus and becomes less visible */
  opacity: .5;
}

.cd-top:hover {
  background-color: #bc0f0f;
  opacity: 1;
}
.cd-top {
  border-radius: 4px;
}