#main-header img {
  width: 100%;
  height: 100%;
}

#main-header .port-item {
  width: 30%;
}

#main-header .port-item:hover {
  opacity: 0.8;
  cursor: pointer;
}

.bg-black {
  color: #fff;
  background: #383637;
}

@media (min-width: 1199px) {
  .port-item {
    padding: 3em !important;
  }
}

@media only screen and (min-width: 768px) {
     #main-header nav {
        display: none;
  }
}

@media only screen and (max-width: 992px) {
      #main-header .novisible {
       display: none;
  }
}

@media only screen and (min-width: 480px) and (max-width: 991px) {
      #main-header h1 {
       font-size: 15px !important;
  }
      #main-header h3 {
       font-size: 24px;
  }
}


/* 2 колонки на sm */
@media (min-width: 576px) {
    .card-columns {
        -webkit-column-count: 1;
        column-count: 1
    }
}
/* 2 колонки на md */
@media (min-width: 768px) {
    .card-columns {
        -webkit-column-count: 2;
        column-count: 2
    }
}
/* 3 колонки на lg и xl */
@media (min-width: 992px) {
    .card-columns {
        -webkit-column-count: 3;
        column-count: 3
    }
}