Product listing quantity input

Hello,

Question 1. & 2. can be done by some css code, follow me step by step :
1. Have a look on this tutorial to see how to add css code
2. Use your browser inspector tool hover your html element to get their html class
3. Build your css custom code.
=> .html_page_class .html_element_class {
command : value;
}
Note : To increase your css command priority, put this code at the end of your css file, and use a page class to restrict your css command to your required page website.

For question 3. we aren't sure to understand what you mean with "description of hr tag not to quantity of symbols", can you details your idea, please.

Regards