Complete solution with VanillaJS and CSS

Hey there!!

So, thats probably the most challenging project so far, cause I had to deal with exceptions (mainly because the app doesn't have a submit button, so the results have to update automatically every time a key pressed) and I used almost all of the knowledge I've been learning, which includes: javascript DOM manipulation, functions, parameters and preventing negative inputs, etc; CSS flexbox, as always, which is becoming usual, but in this case I had to deal with grid too, style inputs (text and radio borders, pseudo elements, disabled states, etc), which was fun and responsiveness.

The behavior I wanted to put in my app is:

• When the user start to type the bill value, the "cant be zero" message shows on the number of people input field, but the focus stays on the bill input;
• When the user chooses a tip on the tip radio buttons (or put a custom value), the message stays, but the focus goes automatically to the number of people field;
• All the results are updated automatically when any of the inputs changes;
• The user can't type any negative value in the input fields;
• The account value input can accept values ​​with two decimal places, while the people input only accepts integers
• Results are only updated if all conditions are met;
• I tried to make the design as accurate as possible.

Things to improve soon:

• Limit the maximum bill value the user can type (I'll do this right now);

Feedbacks are welcome :)