#main {
  display: flex;
  justify-content: center;
}

#forkongithub a {
  background: #000;
  color: #fff;
  text-decoration: none;
  font-family: arial, sans-serif;
  text-align: center;
  font-weight: bold;
  padding: 5px 40px;
  font-size: 1rem;
  line-height: 2rem;
  position: relative;
  transition: 0.5s;
}

#forkongithub a:hover {
  background: #c11;
  color: #fff;
}

#forkongithub a::before,
#forkongithub a::after {
  content: "";
  width: 100%;
  display: block;
  position: absolute;
  top: 1px;
  left: 0;
  height: 1px;
  background: #fff;
}

#forkongithub a::after {
  bottom: 1px;
  top: auto;
}