.channel-button {
  text-align: center;
  display: block;
  max-width: 90%;
  margin: 40px auto 0;
}
.channel-button > a {
  transition: 0.4s;
}
.channel-button > a:hover {
  opacity: 0.7;
}
.channel-button .channel-button-ex {
  margin-top: 10px;
  font-weight: 700;
}
@media screen and (max-width: 640px) {
  .channel-button {
    margin: 20px auto 0;
  }
}