Svelte Guideline: Styling — Use CSS variables as design tokens. Description: All colors radii spacing via CSS variables consumed by Tailwind. Do: --background --foreground --primary --destructive --border --ring. Don't: Hardcoded hex values in component classes. Good Example: class='bg-background text-foreground border-border'. Bad Example: class='bg-white text-gray-900 border-gray-200'. Severity: High. Docs: .