Top Right? Top Left?

I know that there are currently the following locations available:

Right
Left
Middle

Would it be possible to add the following additional options?

Top Right
Top Left

I know which section I need to edit to add the options.

<th scope="row"><?php _e('Box position', 'stb'); ?></th>
                                <td>
                                    <input name="stb_settings[position]" type="radio" value="right" id="bright"
                                           class="tog" <?php checked('right', $options['position']); ?>><label
                                    for="bright"><?php _e('Right', 'stb'); ?></label><br/>
                                    <input name="stb_settings[position]" type="radio" value="left" id="bleft"
                                           class="tog" <?php checked('left', $options['position']); ?>><label
                                    for="bleft"><?php _e('Left', 'stb'); ?></label><br/>
                                    <input name="stb_settings[position]" type="radio" value="middle" id="bmid"
                                           class="tog" <?php checked('middle', $options['position']); ?>><label
                                    for="bmid"><?php _e('Middle', 'stb'); ?></label><br/>
                                </td>

So I could probably add the following code:

<input name="stb_settings[position]" type="radio" value="top right" id="right"
                                           class="tog" <?php checked('right', $options['position']); ?>><label
                                    for="right"><?php _e('Top Right', 'stb'); ?></label><br/>
                                    <input name="stb_settings[position]" type="radio" value="top left" id="left"
                                           class="tog" <?php checked('left', $options['position']); ?>><label
                                    for="left"><?php _e('Top Left', 'stb'); ?></label><br/>

However, where would I edit the actual values? I can’t seem to find a CSS file for the actual positioning of the scrollbox. There are css files for the styling.

Where do I edit the values for bright, bleft, bmid and my two new selector values?

Any advice?

https://www.ads-software.com/plugins/dreamgrow-scroll-triggered-box/