Broken padding in Search block's button

[fullofcaffeine]

Description

The Search block's button's padding is broken. Tested with v10.2.0 (latest version at the time I'm writing this). See screenshot s below (tested with TwentyTwentyOne and Blank Canvas themes).

Step-by-step reproduction instructions

1. Install v10.2.0 in your WordPress instance;
2. Switch to the Blank Canvas theme;
3. Create a new post or page;
4. Insert a Search block;
5. Observe how there's way too much padding at the bottom (or not enough at the other sides) making the button look odd and the text not centered.

Expected behaviour

The button should look well and balanced and not have the odd padding at the bottom.

Actual behaviour

There's way too much padding at the bottom (or not enough at the other sides) making the button look odd and the text not centered.

Screenshots or screen recording (optional)

Twenty Twenty One theme:

Blank canvas theme:

WordPress information

• WordPress version: 5.8-alpha-50538.
• Gutenberg version: v10.2.0.
• Are all plugins except Gutenberg deactivated? Yes.
• Are you using a default theme (e.g. Twenty Twenty-One)? Yes, but also tested with the Blank Canvas theme.

Device information

• Device: Desktop.
• Operating system: Ubuntu Linux 18.04.
• Browser: Firefox Quantum 87.0b9 (64-bit).

[simison]

Checked in Gutenberg 10.5 and TwentyTwentyOne, still happens:

Blank Canvas:

I think this can also be theme-specific since it didn't happen with Alves theme:

Perhaps the block needs to be a bit more defensive about its styles?