@charset "Shift_JIS";
.air-top-btn a{
  display:block;
  color: #fff;
  background: #233498;
  padding: 20px 0;
  margin: 15px 200px;
  font-size: 20px;
  border-bottom: solid 5px rgba(0,0,0,0.3);
  opacity: 1;
  transition: opacity 1s;
  text-align: center;
}
.air-top-btn a:link,
.air-top-btn a:visited
 {
  color: #fff;
}
.air-top-btn a:hover {
  text-decoration: none;
  transition: opacity 1s;
  opacity: 0.8;
}