fix: fix misaligned source icon

[youngyjd]

Summary of Changes

Before:

Now:

Tests

css change. no new unit test created.

Documentation

NA

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[feng-tao]

cc @Golodhros

[kristenarmes]

Looks good on our end
cc @Golodhros

[youngyjd]

I don't have merge access on frontend code. Could @kristenarmes or @Golodhros please take care of it?