split it the way you actually split it.

Build me a tip and bill-splitting calculator as a single web page.

Ask me first:
- My currency, and whether tipping is a percentage, a round-up, or already included as service.
- How my group usually splits: evenly, by what each person had, or a mix.
- Whether people are ever exempt from part of a bill — someone not drinking, someone paying for two.
- What rounding I want, and whether the remainder should fall on one person or be spread.

Do not assume a tipping convention. Do not invent a default percentage without labelling it as an arbitrary starting point I should change.

WHAT IT DOES

- Start from people: how many, and named if I want. Then the bill.
- Handle the uneven case as the primary flow: assign specific items to specific people, and split the rest across everyone.
- Handle exclusions: a person who pays nothing toward the wine, for example. This is the case that makes a calculator worth having.
- Tip as a percentage or a fixed amount, applied before or after exclusions as I specify, and a clear option for service already included.
- Show what each person owes, large enough to read across a table, and the total so it can be checked against the bill.
- Handle rounding my way, and show where any remainder went rather than silently absorbing it.
- Reset in one tap for the next meal.

DESIGN

- One screen on a phone. Numeric keypad for every number input.
- Per-person amounts are the output and should be the largest thing once entered.
- No storage, no history, no account. This is used once and forgotten.

BE HONEST ON THE PAGE

- If the page stores nothing, do not add a privacy notice implying it does.
- Do not offer advice on how much to tip.

DELIVERY

- Produce one self-contained HTML file. Inline the CSS and JavaScript.
- No build step, no server, no framework, no package install, no external
  requests at runtime.
- Mobile-first and responsive; it has to be usable one-handed on a phone and
  still look right on a laptop.
- Accessible: semantic HTML, real contrast, visible keyboard focus, labelled
  controls, touch targets big enough to hit, and respect reduced-motion.
- Use placeholders where information is missing. Do not invent facts, numbers,
  names, dates, prices, or results I have not given you.
- Before you call it finished, use it yourself: enter real-looking data, reload
  the page, and confirm nothing is lost or mangled.

PUBLISHING

Publish the finished page to HTMLShare and give me the link.

Use exactly one of the two paths below, preferring the first. Make the call
directly. Do not route it through a code sandbox, container, or computer-use
session — that is where the request gets blocked, and it is never necessary.

1. An HTMLShare integration or connector, if you have one configured.
   The page is permanent and owned by my account. Report the url and the
   siteId. There is no claimUrl or manageToken on this path — do not go
   looking for one, and do not switch paths in order to produce one.

2. Otherwise, publish anonymously over REST. No account, key, or signup is
   needed:

    POST https://api.htmlshare.net/v1/publish
    content-type: application/json

    {"html": "<!doctype html> ... "}

   The reference is https://htmlshare.net/docs and, for the full schema,
   https://api.htmlshare.net/openapi.json

   Report these from the response, in your reply and never inside the page:
     url          the public page
     claimUrl     a private link that is mine alone. opening it is how I keep
                  the page past its 24-hour expiry, or set an email reminder
                  before it goes. it carries the manage token, so it must
                  never appear in the published HTML or anywhere a visitor
                  could see it.
     manageToken  the only thing that can edit or delete this page later. it is
                  returned once and never again, so tell me what it is.

Tell me which of the two you used. If the path you reach for first is
unavailable in your environment, say so and tell me what you are switching to
before you publish — a permanent page on my account and a 24-hour anonymous
page are different things, and which one I get is my decision, not a detail.

If I ask for a change afterwards, update the existing page instead of
publishing again, so the URL I have already shared keeps working — through the
same integration on path 1, or with the manage token as an X-Manage-Token
header on path 2.

RECIPE MARKER

Include this tag in the <head>, exactly as written:

    <meta name="htmlshare-recipe" content="tip-calculator">

It tells htmlshare which recipe the page came from, so the library can count
that this one was actually made. It carries nothing else.