app/assets/stylesheets/variables.css
:root {
--yellow: hsl(48, 89%, 50%); /* #f1c40f */
--lighter-yellow: hsl(48, 89%, 60%);
--darker-yellow: hsl(48, 89%, 45%);
--color-primary: #020d18; /* hsl(210, 85%, 5%) */
--color-secondary: var(--yellow);
--color-secondary-lighter: var(--lighter-yellow);
--color-secondary-darker: var(--darker-yellow);
--color-links: lightblue;
}