This is different Request, How Can I size the “Post your item” button color frame? For the text on it is standart size, not customizable i think, How could I access this button size, color, line or other options scripts to make it little more thinner vertically. Thank you
You can override this and define extra CSS properties by clicking customize your theme in “Appearance” -> “Themes”. When you click “Customize” on new page you will see “Custom styles” section, put your custom CSS code there.