1. variables.css: Added --light-color-rgb: 255, 255, 255; and --opacity: 0.3
2. background.css:
a. Updated --background-secondary: var(--grey-color);
b. Added --background-primary-rgb:var(--primary-color-rgb);
c. Added rule for ".uk-background-primary-opacity".
1. background.css: :not(.uk-preserve-color) removed from uk-background-primary | color is defined separately for primary backgrounds (uk-preserve-color affects only text color).
2. button.css: NEW variable --button-primary-color-hover.
3. text.css: Set --font-default-color: #4b4b4b; | Apply primary color to primary section too.