Create a concise, stylish, and modern investment calculator.

Create a concise, stylish, and modern investment calculator.

It should allow users to input:

1. Initial investment amount
2. Investment term in years
3. Additional investment amount, with the option to switch between monthly or annual frequency
4. Assumed annual return rate (8% is recommended)

Assume the additional investment amount remains constant.
Interest is calculated based on the balance.
The calculation should take into account whether the additional investment frequency is monthly or annual.

It should include some explanations on how to use the calculator and key concepts such as compound interest.

The results should dynamically display "In {duration} years, by investing {contributions} monthly/annually, your investment could be worth $XX,XXX", along with a chart showing the comparison between the potential value of the investment and the total amount invested after the specified period, and a table detailing the annual initial balance, total investment amount, earnings, and ending balance.

Please provide this content in HTML format.