gentelella/vendors/datatables.net-buttons-bs/css/buttons.bootstrap.css

div.dt-button-info {
  position: fixed;
  top: 50%;
  left: 50%;
  width: 400px;
  margin-top: -100px;
  margin-left: -200px;
  background-color: white;
  border: 2px solid #111;
  box-shadow: 3px 3px 8px rgba(0, 0, 0, 0.3);
  border-radius: 3px;
  text-align: center;
  z-index: 21;
}
div.dt-button-info h2 {
  padding: 0.5em;
  margin: 0;
  font-weight: normal;
  border-bottom: 1px solid #ddd;
  background-color: #f3f3f3;
}
div.dt-button-info > div {
  padding: 1em;
}

ul.dt-button-collection.dropdown-menu {
  display: block;
  z-index: 2002;
  -webkit-column-gap: 8px;
  -moz-column-gap: 8px;
  -ms-column-gap: 8px;
  -o-column-gap: 8px;
  column-gap: 8px;
}
ul.dt-button-collection.dropdown-menu.fixed {
  position: fixed;
  top: 50%;
  left: 50%;
  margin-left: -75px;
  border-radius: 0;
}
ul.dt-button-collection.dropdown-menu.fixed.two-column {
  margin-left: -150px;
}
ul.dt-button-collection.dropdown-menu.fixed.three-column {
  margin-left: -225px;
}
ul.dt-button-collection.dropdown-menu.fixed.four-column {
  margin-left: -300px;
}
ul.dt-button-collection.dropdown-menu > * {
  -webkit-column-break-inside: avoid;
  break-inside: avoid;
}
ul.dt-button-collection.dropdown-menu.two-column {
  width: 300px;
  padding-bottom: 1px;
  -webkit-column-count: 2;
  -moz-column-count: 2;
  -ms-column-count: 2;
  -o-column-count: 2;
  column-count: 2;
}
ul.dt-button-collection.dropdown-menu.three-column {
  width: 450px;
  padding-bottom: 1px;
  -webkit-column-count: 3;
  -moz-column-count: 3;
  -ms-column-count: 3;
  -o-column-count: 3;
  column-count: 3;
}
ul.dt-button-collection.dropdown-menu.four-column {
  width: 600px;
  padding-bottom: 1px;
  -webkit-column-count: 4;
  -moz-column-count: 4;
  -ms-column-count: 4;
  -o-column-count: 4;
  column-count: 4;
}

div.dt-button-background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2001;
}

@media screen and (max-width: 767px) {
  div.dt-buttons {
    float: none;
    width: 100%;
    text-align: center;
    margin-bottom: 0.5em;
  }
  div.dt-buttons a.btn {
    float: none;
  }
}