Limiting Text Input with Jquery | like Twitter

Jquery limit input
Some time ago I was asked to make a web application for the purpose of a story writing competition, the story can only be 700 characters long.

How to keep the data stored in the database no longer than 700 characters?

Also, how do you let the user know how many characters they have written (part of the user experience)?

There are 2 ways that can be used.

Restricting with PHP (Server site)
Restricting with Javascript/Jquery (Client site)
This time will be discussed with Javascript, especially using Jquery.

What will it be like?
What we make may be similar to twitter, where twitter limits users by only allowing to write 140 characters for each post status.

Similar to the case of limiting characters to the story.

How to make it?

HTML structure (index.html)