### What problem does this PR solve?
Fix: Optimized the table of contents style and homepage card layout
#3221
- Added background color, text color, and shadow styles to the Markdown
table of contents
- Optimized the date display style in the HomeCard component to prevent
overflow
- Standardized the translation of "dataset" to "knowledge base" to
improve terminology consistency
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)