Student Grades Form Webpage

I need a straightforward webpage that lets me type in each student’s name, their score, and the resulting proficiency level through a clean form interface—no file uploads or database hooks, just quick manual entry. As soon as I submit a record the page should display it in a running table, automatically clearing the form for the next student. Totals and basic class statistics (highest, lowest, mean score) should update live at the bottom of the table.

A default A-F scale is fine if it simplifies the build, but keep the logic flexible in a single place in the code so I can tweak thresholds later. All calculations should run in-browser; storing data in localStorage is enough for now—no server needed. Deliver the complete HTML, CSS, and vanilla JavaScript (or a lightweight framework like React if you prefer) plus a brief README explaining where to change grading cut-offs and how to reset stored data.