@media (min-width: 1200px) {

.container, .container-lg, .container-md, .container-sm, .container-xl {
    max-width: 1550px;
}

}

@media (max-width: 911px) {

    .mainYoutube {
      width: 95%;
      height: 300px;
  }

  #first-box:after {
    display: none;
  }

  .logo img {
    vertical-align: unset;
  }

  .navbar-nav {
    margin: 0px;
  }

  header .orange-btn {
    margin-left: 0px;
    margin-top: 15px;
    display: inline-block;
  }

}

  @media (max-width: 768px) {

    .mainYoutube {
      width: 100%;
      margin-top: 70px;
    }

    .top-img {
      margin: auto;
      left: 0;
      right: 0;
      display: block;
    }


  }

  @media (max-width: 468px) {

    .mainYoutube {
      height: 250px;
    }

    .logo img {
      height: 30px;
    }

  }