fix: Improved view transition animation for post titles

[Yamabuki-bakery]

Description

The view transition animation of the "Post Title (h1, h2, h3...)" between the post list pages and the post pages is weird,
because of the width mismatch of titles among these pages.

Solution:
Making the title in post page an inline-block, like what a title on list page is.

See slow motion video:

Currently:

default.mp4

After fix:

default.mp4

Types of changes

• Bug Fix (non-breaking change which fixes an issue)
• Others (any other types not listed above)
• New Feature (non-breaking change which adds functionality)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the Contributing Guide
• I have added the necessary documentation (if appropriate)
• Breaking Change (fix or feature that would cause existing functionality to not work as expected)

Further comments

None

Related Issue

None