Improve layout and reduce whitespace in home page sections

[carboitel]

Description:

• Updated the layout of the "Features" section to display icons above titles with two rows and three columns.
• Reduced unnecessary whitespace between elements in the features section by adjusting grid and flexbox settings.
• Increased vertical padding below the "Features" heading for better spacing.
• Reduced horizontal spacing in the main content and section areas for a more compact layout.

Changes:

• Adjusted grid system to align icons above titles and create a two-row, three-column layout.
• Applied gap adjustments to reduce horizontal and vertical space between content blocks.
• Tweaked margin and padding values for the "Features" heading and other components to improve spacing consistency.

Screenshots:

Issue reference:

Resolves Issue #322