mdb-ui-kit/scss/_modal.scss

// Modals
// https://www.google.com/design/spec/components/dialogs.html#dialogs-specs

.modal-content {
  border: 0;
  border-radius: $border-radius;

  .modal-header {
    padding: 24px 24px 0;
    border-bottom: 0;
  }
  .modal-body {
    padding: 20px 24px 24px;
  }
  .modal-footer {
    padding: 8px 8px 8px 24px;
    border-top: 0;
    .btn {
      margin: 0;
    }

    .btn + .btn {
      margin-left: 8px;
    }
  }
}