weseek__growi/apps/app/src/styles/_modal.scss

@mixin expand-modal-fullscreen($hasModalHeader: true, $hasModalFooter: true, $margin: 1rem) {
  // full-screen modal
  width: auto;
  max-width: unset !important;
  height: calc(100vh - $margin * 2);
  margin: $margin !important;

  .modal-content {
    height: calc(100vh - $margin * 2);
  }
  .modal-body {
    padding: $margin;
  }

  // expand .modal-body (with calculating height)
  .modal-body {
    $modal-header: 54px;
    $modal-footer: 46px;
    $margin-body: 0;

    @if $hasModalHeader {
      $margin-body: $margin-body + $modal-header;
    }

    @if $hasModalFooter {
      $margin-body: $margin-body + $modal-footer;
    }

    height: calc(100% - #{$margin-body});
  }
}

// expanded window layout
.modal-dialog.grw-modal-expanded {
  @include expand-modal-fullscreen(true, true);
}

// expanded window layout without modal-header & modal-footer
.modal-dialog.grw-body-only-modal-expanded {
  @include expand-modal-fullscreen(false, false);
}