UI yaml editor active line unreadable in dark mode

[VDRainer]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.

Describe the issue you are experiencing

The active line in the UI yaml editor has a white background, so some text is unreadable in dark mode.
See screenshot in Additional information.

Describe the behavior you expected

See the code

Steps to reproduce the issue

...

What version of Home Assistant Core has the issue?

core-2021.3.1

What was the last working version of Home Assistant Core?

core-2021.3.0

In which browser are you experiencing the issue with?

Latest FF and Chrome

Which operating system are you using to run this browser?

Ubuntu 18.03

State of relevant entities

# Paste your state here.

Problem-relevant frontend configuration

# Paste your YAML here.

Javascript errors shown in your browser console/inspector

# Paste your logs here.

[spacegaier]

Yes, we are already aware and it will most likely be fixed in dev tonight.