Blog summary thumbnail size

Theme: virtue free

I like this theme. It is simple and straightforward.
I have one problem at blog post summary.
My setting at theme option is;
Blog Post Default-> Blog Post Summary Default->Portrait Image
The size of thumbnail(from featured image) is too big for me and I want to reduce it.
I found the size is set to 365×365 square. I want to change it to 150 x 150, for example.
Will you please show me how to change it by custom css?

Also is it possible to display all thumbnail in same size?
Is it cropped or proportionally reduced?

• This topic was modified 5 years, 8 months ago by cksong.