UI polish: whitespace + smooth scrolling

Two small changes that together add up to a noticeable lift.

Whitespace

Several surfaces feel cramped or uneven because the spacing tokens get applied inconsistently. Notably:

• Section gaps on the Life Plan main page sit closer than they should
• The two pillar cards on Life Plan and the sections below them don't share a clear vertical rhythm
• Card components across surfaces use slightly different internal paddings
• Long titles wrap into tight line-heights that read busy

The job is not to add space everywhere. It is to pick a vertical rhythm (probably 32 / 48 / 64 / 96 from the existing spacing tokens) and apply it consistently. Make the page feel like a designed document, not a wall of cards.

Smooth scrolling

Globally apply scroll-behavior: smooth on the html element, plus a sensible scroll offset so in-page anchors don't slam content under the sticky nav. Respect prefers-reduced-motion so people who turn motion off still get instant jumps.

For the back-to-top affordance on long pages (Master Plan, long writeups), consider a quietly fading button that appears after a scroll threshold and animates the scroll-to-top.

Out of scope here

This entry is about feel, not features. Anything that needs new components or new data goes in its own idea.