[blog] Improve readability of wrapped post titles in the Recent Posts sidebar

**Task description**:

Improve the readability of wrapped blog post titles in the **Recent Posts** sidebar on the blog page.

Currently, long post titles wrap onto multiple lines, but the wrapped text appears visually cramped due to insufficient spacing. This makes the sidebar harder to scan and results in an inconsistent visual appearance compared to the rest of the page.

The issue can be observed on the `/blog` page in the **Recent Posts** sidebar, where titles such as:

- `OSPP-2025 Documentation Automation`
- `OSPP-2025 eBPF Program UT Enhancement`

wrap onto multiple lines with tight line spacing.

The goal of this task is to improve the typography and spacing of the sidebar while preserving the existing layout and responsive behavior.

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**Solution**:

Investigate the CSS and/or component responsible for rendering the **Recent Posts** sidebar and improve the readability of wrapped titles.

Possible improvements include:

- Increase the `line-height` of wrapped post titles.
- Add appropriate vertical spacing (`margin` or `padding`) between sidebar entries.
- Review the sidebar width or typography if necessary to reduce unnecessary wrapping.
- Ensure the updated styling remains consistent across desktop and mobile viewports.

The final result should provide a cleaner and more readable sidebar without affecting the existing functionality.

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