how to change background colour and font size on shop cart page please?

Site URL: https://www.shirleyhottier.com/cart

Hi there, Could someone help with changing the colour of my background as well as the size of the font for my shop cart page, please?

I would like to use hsl 332/82/84 for the background and brandon-grotesque 400 for the text... Cannot seem to find how to do so anywhere...

Add to Home > Design > Custom CSS

body#cart main#page {
    background: red;
}
body#cart main#page * {
    color: white;
    font-family: monospace;
}

replace with your font, color...