@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;700&display=swap");
:root {
  --bgcolor:#C4E538;
}

* {
  margin: 0;
  padding: 0;
  font-family: "Poppins", sans-serif;
  box-sizing: border-box;
}

body {
  width: 100vw;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #2f3640;
}

.btn {
  background-color: var(--bgcolor);
  border: none;
  padding: 20px 30px;
  font-size: 30px;
  color: #2f3640;
  font-weight: 500;
  border-radius: 5px;
  width: 300px;
  position: relative;
  cursor: pointer;
}
.btn::after, .btn::before {
  content: "";
  width: 25px;
  position: absolute;
  transition: 0.5s;
}
.btn::before {
  border-top: 8px solid var(--bgcolor);
  top: -15px;
  left: 0;
}
.btn::after {
  border-bottom: 8px solid var(--bgcolor);
  bottom: -15px;
  right: 0;
}
.btn:hover::after, .btn:hover::before {
  width: 100%;
}