<a href="#" class="btn">Button name</a>

body {
  background-color: #f1e7e3;
  padding: 40px;
  font-family: sans-serif;
}

.btn {
  display: inline-block;
  border: 2px solid #FFF;
  background-color: #4481b3;
  padding: 10px 20px;
  border-radius: 20px;
  text-decoration: none;
  color: #FFF;
  position: relative;
  text-transform: uppercase;
  font-size: 14px;
}

.btn:hover {
  background-color: #194365;
  transition: all 0.5s;
}

.btn:hover:before, .btn:hover:after {
  border-color: #194365;
}

.btn:before {
  content: '';
  display: block;
  border-left: 2px solid #ed6a37;
  border-top: 2px solid #ed6a37;
  border-top-left-radius: 25px;
  width: 25px;
  height: 25px;
  position: absolute;
  top: -7px;
  left: -7px;
  transition: all 0.5s;
}

.btn:after {
  content: '';
  display: block;
  border-right: 2px solid #ed6a37;
  border-bottom: 2px solid #ed6a37;
  border-bottom-right-radius: 25px;
  width: 25px;
  height: 25px;
  position: absolute;
  bottom: -7px;
  right: -7px;
  transition: all 0.5s;
}