@wiris/mathtype-ckeditor5/theme/styles.css

MathType Web for CKEditor5 editor

/* Replace the default suggestion marker border because it's doesn't span the entire widget. */
.ck-widget.ck-math-widget.ck-suggestion-marker {
  border: none;

  &.ck-suggestion-marker-insertion {
    & .Wirisformula {
      border: 3px solid var(--ck-color-suggestion-marker-insertion-border);
    }

    &.ck-suggestion-marker--active {
      & .Wirisformula {
        border: 3px solid var(--ck-color-suggestion-marker-insertion-border-active);
      }
    }
  }

  &.ck-suggestion-marker-deletion {
    & .Wirisformula {
      border: 3px solid var(--ck-color-suggestion-marker-deletion-border);
    }

    &.ck-suggestion-marker--active {
      & .Wirisformula {
        border: 3px solid var(--ck-color-suggestion-marker-deletion-border-active);
      }
    }
  }
}