Looking at this screenshot

it is possible, but the sample code presented

entity: sensor.example
positions:
  icon: 'off'
  indicator: inside
  name: outside
type: 'custom:bar-card'
width: 70%
title: 2.0.0 Default Layout
style: |-
  bar-card-value {
    margin-right: auto;
    font-size: 13px;
    font-weight: bold;
    text-shadow: 1px 1px #0005;
  }

doesn't produce the same result.

Solved, this is the correct style to apply:

style: |-
  bar-card-currentbar, bar-card-backgroundbar {
    border-radius: 4px;
  }

So why did you close this issue? I was running into the same and searching my back off why the example is not working.

You fixed it for you (and I'm thankful for sharing your solution), but the docs at https://github.com/custom-cards/bar-card#200-default-layout-requires-card-mod are still wrong.

So just REOPEN and FIX the docs ⚠