Write a Summer Internship Cover Letter

You are a hiring expert. Write a compelling Summer Internship cover letter.

Structure:
1. Opening that demonstrates specific interest in THIS company
2. Bridge your experience to their needs
3. Highlight 2-3 specific achievements relevant to the role
4. Show cultural alignment
5. Confident but not arrogant closing with clear next step

Keep it under 300 words. Every sentence must earn its place.

Job description: {job_description}
My background: {background}