Images not being sized

Hosting on Micro.blog
1

Trying to do a longer form blog post with included images. Preview looks exactly how I want it, with 3 images next to each other, but every time I post I get larger images stacked on top of each other.

I’m using the IMG tag directly, calling the small (-s) image from CDN and specifying the height=300 width=300 but makes no difference to the displayed.

2

Does your theme have something like:

img {
  min-width: 100%
}

or similar in the CSS?

3

no idea - 0.91 Sumo theme -is this adding it to the box on ‘Edit CSS’?