Button Text Spacing and Alignment with CSS Help

Hi!

I'm using CSS to adjust my button text.

I'd like there to be no padding (or space) on the left of my button text so that everything lines up. I tried adjusting the padding to 0vw and the text alignment and it moved but it's still not fully aligned left. See attached screenshot. 

send-again.squarespace.com
PW: sendagain

Would love to know what I'm missing. 

Thank you!

Use this code to Website Tools (under Not Linked) > Custom CSS

div#block-yui_3_17_2_1_1705087128851_54832 a {
    justify-content: flex-start !important;
}

Thank you so much @tuanphan!