.channel-img {
  width:16.6666666667%;
  opacity:1;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.channel-img:hover {
  opacity:.8;
  transform: scale(1.07); /* aumenta 7% */
}

/* RESPONSIVO */
@media (max-width: 990px) {
  .channel-img {
    width:20%;
  }
}
@media (max-width: 768px) {
  .channel-img {
    width:25%;
  }
  .d-md-flex {
    display:flex!important;
  }
}
@media (max-width: 600px) {
  .channel-img {
    width:33.3333333333%;
  }
}
@media (max-width: 400px) {
  .channel-img {
    width:50%;
  }
}

/* FLEX UTILITIES */
.d-flex {
  display:flex!important;
}
.flex-wrap {
  flex-wrap:wrap!important;
}
.justify-content-center {
  justify-content:center!important;
}