fix: reduce empty space between modules

[PelleNybe]

The UI had multiple inline styles applying hardcoded margins (e.g. margin-top: 6rem) to section tags which caused them to have long, inconsistent spacing between modules.

• Removed explicit inline margin properties on <section> elements within index.html.
• Reduced the global CSS property --spacing-xl applied on the <section> tag's standard vertical padding from 5rem to 3rem (--spacing-lg).
• Reduced .hero-content top margin from 150px to 120px.
• Rebuilt minified site outputs dist/.

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PR created automatically by Jules for task 11327475747864157782 started by @PelleNybe

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