Summary: 데이터리안 updates course early bird deadlines to D-3

Why It Matters: The competitor is creating urgency for their upcoming SQL and GA4 data analysis camps. They are moving closer to their March 1st registration deadline.

What Changed:

• Updated the early bird countdown from D-4 to D-3 for all main courses.
• Refreshed the "Popular Blog Posts" section with new articles about SQL cheat sheets and data book recommendations.
• Swapped several recommended articles in the "Editor's Choice" section, including new case studies from Toss and Karrot.
• Removed a duplicate social media link fragment from the footer area.