can't set styles for last_changed

[a-bianucci]

Checklist

• [X ] I updated the card to the latest version available
• [ ] I cleared the cache of my browser

Describe the bug I can get the "show_last_changed: true" to function, however I can't style it in the "Styles" section by leveraging last-changed, or last_changed

Version of the card Version: 3.4.2

To Reproduce This is the configuration I used:

type: custom:button-card
entity: light.kitchen_bar
show_name: false
styles:
  card:
    - height: 100px
    - background-color: rgba(0,0,0,0.0)
    - box-shadow: 0px 0px 0.0px 0px
  grid:
    - position: absolute
  name:
    - align-self: start
    - justify-self: center
    - font-size: 24px
    - color: rgb(128,128,128)
  last_changed:
     - font-size: 10px

Screenshots If applicable, add screenshots to help explain your problem.

Expected behavior A clear and concise description of what you expected to happen.

I would expect that any styles could be applied

Desktop (please complete the following information):

• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context Add any other context about the problem here.