a {
  text-decoration: none;
}

.ov-btn-slide-left {
  background: #fff;
  color: #4741d7;
  border: 2px solid #4741d7;
  padding: 16px 20px;
  border-radius: 3px;
  position: relative;
  z-index: 1;
  overflow: hidden;
  display: inline-block;
}

.ov-btn-slide-left:hover {
  color: #fff;
}

.ov-btn-slide-left::after {
  content: "";
  background: #4741d7;
  position: absolute;
  z-index: -1;
  padding: 16px 20px;
  display: block;
  top: 0;
  bottom: 0;
  left: -100%;
  right: 100%;
  -webkit-transition: all 0.35s;
  transition: all 0.35s;
}

.ov-btn-slide-left:hover::after {
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  -webkit-transition: all 0.35s;
  transition: all 0.35s;
}