Thumbnail

If the post contains a video, the image from it is displayed as the cover of the post, regardless of the size of the other images. Please tell me how to choose the first picture in the post for the thumbnail. And also how do I mark the borders of the text, for display near the cover. I found a discussion on this topic but couldn't apply it to my template.

How can I ensure that the first image in my post is displayed as the default image when sharing the link on social media?

Is there a way to show the first frame (or just any image) of a (local) video (located in the same folder as the .md file) as a preview image rather than just the play icon? This seems to work fine for external video hosted on Youtube, but does not seem to work for video stored in the same folder

How does the magazine template determine when/which image to show in an entry's listing? Many of my posts have images, but only some appear to the right of the listing on the main page, and I can't figure out what factor determines when an image is pulled there.