How to get consistent button sizes? - 7.0

Site URL: https://oboe-gold-frbd.squarespace.com/register

The site password is: hotballoon1

SS by default adjusts the width of the three buttons based on their text. How can I get all three buttons to be the same length?

P.S. if anyone also knows how to adjust the buttons colors individually, please let me know. It'd be nice to have more colorful buttons

Setting color style for each button via the following code

#block-yui_3_17_2_1_1658339303941_3946 a {
  background: red;
}

#block-yui_3_17_2_1_1658339303941_5356 a {
  background: blue;
}

#block-yui_3_17_2_1_1658339303941_3003 a {
  background: green;
}

To get the right id for block you can use the following extension: Squarespace Id finder

How to use it: https://recordit.co/kUIH4uco0b

Hope it makes sense