Resize "what's my size button" venture theme

Hi everyone!
i would like to resize the “what’s my size” button ( see link below)
https://blacksanctuary.eu/products/believe-nothing
actually the font is good like this, i just would like to resize the “frame” around the text as something like this : ( see photo )
is that possible?
thank you!

@Blacksanctuary

please Go to Online Store->Theme->Edit code then go to assets/theme.scss.liquid ->paste below code at the bottom of the file.

.template-product .btn {
    padding: 15px 15px !important;
}

hello @Blacksanctuary

please Go to Online Store->Theme->Edit code then go to assets/theme.css ->paste below code at the bottom of the file.

.btn.ks-calculator-modal-button.sizing-calculator-modal-button{
	
	padding: 12px;
}

thank you so much!! is there a way to make it more thin also up and down and not only the corners? thanks again!