body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN";
}

a {
  text-decoration: none;
}

.buttom a{
  transition: 1.5s;
  border-radius: 3px;
  color:black;
  font-family:serif;
}

.buttom a:hover{
  background-color:#c1c1c1;
}