Common primary/background colours I use so I don't forget

theme.css

:root {
    --primary: #192734;
    --primary-alt: #384047;
    --background: #f2f2f2;
    --surface: #caccce;
}

:root[data-theme="dark"] {
    --primary: rgba(255, 255, 255, 0.85);
    --primary-alt: rgba(217, 217, 217, 0.85);
    --background: #242424;
    --surface: hsla(0, 0%, 40%, 0.48);
}