Changing featured image size on specific pages using CSS – Edin Theme

Hi,

I’ve successfully used the CSS Stylesheet Editor (through Jetpack) to edit the height that the featured image appears on pages on my site, using:

.page .hero.with-featured-image {
padding: 90px 0;
}

The above I found on another forum thread. Now I’d like to change the dimensions of the featured image at the top of the page for just one specific set of pages. For this set of pages (all child pages of my About page) I’d like to set the featured image to appear in central portrait dimensions (If poss 2:3). I thought of perhaps doing this by adding a command that only targets a specific page template, but have been struggling to achieve this.

I’ve been trying just to reduce the size of the header these specific pages with things along the lines of:

.page-templates-full-width-page .hero.with-featured-image {
padding: 5px 0;
}

As the relevant page template in the php is “page-templates/full-width-page.php”

Any advice on where I’m going wrong? If its going to be complicated to set the featured images on these specific pages to appear portrait, can anyone help me just disable them for this group of pages. (I can’t just remove them because they appear in the Grid Format on the parent About page.)

Hope this all makes sense, I’m a relative newbie.

Thanks,
Alex