Visual Refresh of Docs UI (`style.css` only)

Start with style.css and review the existing rules for the hero, sidebar, CTA, animation list, header, code blocks, and layout. Visually verify standard, dark, and reduced-motion settings, including clipboard, toggles, and animation demos; done means the CSS-only refresh meets the listed visual and accessibility goals without functional regressions.

Summary: Visual Refresh of Docs UI (style.css only)

Scope:

• All changes are CSS-only (style.css)
• No edits to HTML, JavaScript, or content
• Visual and polish-focused (colors, layout, shadows, typography, UI tokens)
• Dark mode rules deliberately left untouched (follow-up planned)

Goals:

• Modernize documentation UI
• Increase professionalism and subtlety in visual design
• Maintain or improve accessibility
• Preserve all existing functionality (no behavioral changes)

Key Improvements:

• Introduced a clean, neutral color palette (slate & blue, better theming)
• Established UI tokens for radius and elevation (more consistent styling)
• Refined typography: better line-height for reading, lighter h1, improved font selection
• Flatter, more modern buttons: blue accent, reduced radius, softer shadow
• Hero section: removed heavy white box, tightened spacing for clarity
• Sidebar: now a professional card (white background, soft border, gentle shadow, consistent padding)
• CTA button: inline & pill-shaped on wide screens (more integrated with hero)
• Animation list: removed decorative gradients, hovered states are more subtle
• Docs header: minimal, subtle border—no gradients or deep shadows
• Code blocks: darker background, subtle border/radius, no heavy shadow
• Layout: set max container width, harmonized spacing for easier reading
• Visual polish: reduced border radii and heavy shadows throughout; gentler hover effects

Accessibility:

• Maintained all prefers-reduced-motion/accessibility rules
• Improved contrast and readability
• No changes to dark mode (for stability—suggested as a follow-up)

File changes:

• style.css: all changes are within this file

Reviewer notes:

• Please visually verify:
  • Hero callout has no white box, CTA is inline on desktop
  • Sidebar uses new card style
  • All features (clipboard, toggles, animation demos) still work
• Test standard, dark, and reduced-motion settings for regressions
• Recommend follow-up PR for dark mode harmony

Suggested PR Title:
style(docs): professional visual refresh for docs (palette, typography, sidebar, CTA)