Undesired scrollbars in markdown area of QuickStart

Description of problem:

Undesired scrollbars appear in markdown area of QuickStart.
There are hardcoded styles present in the iframe rendering the markdown.

Prerequisites (if any, like setup, operators/versions):

Default quickstarts must be there

Steps to Reproduce

Open a quickstart and start it.
Resize the browser window.

Actual results:

Markdown areas show unnecessary scrollbars

Expected results:

Markdown area should not show scrolls.

Reproducibility (Always/Intermittent/Only Once):

Intermittent

Build Details:

OpenShift version 4.7.0-0.nightly-2021-01-12-203716
Kubernetes version v1.20.0+32efea9
Channel stable-4.7
Cluster ID 0272754a-bcd3-4e18-9997-feeeebce997f
API server https://api.dev-svc-4.7-011307.devcluster.openshift.com:6443

Additional info: