It looks like a blogdown site using the hugo icarus theme? I use the same base but prefer some of the options your site incorporates. e.g 3 column landing page but 2 column for actual posts. Is the config.toml and any other relevant files available for viewing?
You are correct that we are using the hugo-icarus theme, but we heavily customized it. You cannot achieve the same style as the RViews blog simply by configuring options in config.toml. Unfortunately the RViews blog repo is not public (which was an intentional choice), so you cannot really view it. Sorry. You will have to ask the theme author for help, or hack at it by yourself.