This question has been answered by donshakespeare. See the first response.
Altering the Form
You can make many changes to the look of the form using CSS rules for styling. You can find the CSS form at assets/components/newspublisher/css/newspublisher.css. Using CSS, you can change the text color, background color, size, and/or position of any field, though the control of richtext fields is limited. You can put fields side-by-side by using "display:inline;" for the appropriate field(s). If you plan to make changes, it's recommended that you make a copy of the CSS file, the assets/components/newspublisher/css directory and put the name of your new file in the &cssfile property.
If you feel you must, you can alter the Tpl chunks for any of the field types. Again, you should duplicate the existing chunk and put the name of your duplicate in the appropriate property. Be careful not to change the prefixes of any of the placeholders, even if you specify a custom prefix for the form as a property. The prefixes will be altered automatically by the snippet. Note that there are both np. and npx. prefixes. The npx. prefixes are used internally by the snippet, the np. prefixes are usually in the value field of the
&cssfile=`0`
Thanks donshakespeare,Well, open the page with NewsPublisher, do &cssfile=`0` as already suggested; then get all the classes/ids of the elements NewsPublisher uses, and style them manually, toss the CSS in your website's bootstrap, group things so that these NP elements use existing styles.
But I already found that tutorial. Fact is that my Bootstrap css file is loaded in the head section, so it counts for the complete page.
If I follow that tutorial from bobsguides, then the css file needs to be in the assets/components/newspublisher/css folder. So I have to load the bootstrap css file two times in that case, and that is just what I try to avoid.