TaniCSS · hesam-oxe · Aug 15, 2026 · Aug 15, 2026 · Aug 18, 2026 · Aug 18, 2026
diff --git a/404.html b/404.html
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+<!DOCTYPE html>
+<html lang="en" data-theme="dark">
+<head>
+<meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1">
+<title>404 — Tani CSS Framework</title>
+<meta name="description" content="Tani 404 — page not found">
+<link rel="stylesheet" href="./dist/css/tani.css">
+<link rel="stylesheet" href="./assets/docs.css">
+</head>
+<body>
+<header class="doc-header">
+  <a class="doc-brand" href="./index.html"><span class="logo-mark">T</span>Tani<b>.css</b></a>
+  <div class="doc-header-actions"><a class="doc-icon-btn" href="./index.html">Docs</a><a class="doc-icon-btn" href="https://github.com/TaniCSS/Tani" title="GitHub">&#9733;</a></div>
+</header>
+<main class="doc-page-wrap">
+
+<div class="doc-404">
+  <div class="big">404</div>
+  <h2>Page not found</h2>
+  <p class="text-muted">The page you are looking for drifted into the void. Let us get you back.</p>
+  <div class="d-flex gap-3 mt-3">
+    <a class="btn btn-primary" href="./index.html">Back to docs</a>
+    <a class="btn btn-outline-primary" href="./index.html#playground">Open playground</a>
+  </div>
+</div>
+</main>
+<footer class="doc-footer"><span>Tani CSS Framework — zero-JS, zero-build. MIT Licensed.</span><span><a href="./index.html">Docs</a> · <a href="https://github.com/TaniCSS/Tani">GitHub</a></span></footer>
+<script src="./assets/docs.js"></script>
+</body>
+</html>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
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+# Contributing to Tani
+
+Thanks for your interest in improving Tani!
+
+## Ground rules
+
+1. **Additive by default** — new versions only add classes, never rename or remove existing ones.
+2. **Zero-JS first** — prefer CSS-only mechanisms (`:checked`, `:target`, `:focus-within`, `<details>`, `<dialog>`) over scripts.
+3. **Logical properties** — use `margin-inline`/`padding-block`/`inset-*` so RTL works for free.
+4. **Respect reduced motion** — every new animation needs a `prefers-reduced-motion` story.
+5. **One source of truth** — before adding a rule, search the stylesheet. If the selector already exists, extend it instead of appending a competing definition (duplicate definitions are how most of our historical bugs happened).
+
+## Workflow
+
+```bash
+git clone https://github.com/TaniCSS/Tani.git
+cd Tani
+# open index.html in a browser — that's the whole toolchain
+```
+
+- Edit `dist/css/tani.css` (the single source file).
+- Regenerate the minified build after changes:
+
+```bash
+python3 tools/minify.py dist/css/tani.css dist/css/tani.min.css
+```
+
+- Run the smoke test if you have Chrome/Chromium available (paths auto-detected):
+
+```bash
+python3 tests/smoke_selenium.py
+```
+
+## Submitting
+
+1. Fork, then create a feature branch (`feat/my-component` or `fix/issue-123`).
+2. Include a live demo built with Tani classes — screenshots are appreciated.
+3. Keep PRs focused; one component/fix per PR.
+4. Update `README.md` and `index.html` docs when you add user-facing classes.
+
+## Reporting bugs
+
+Open a [GitHub issue](https://github.com/TaniCSS/Tani/issues) with:
+- the exact HTML/classes involved,
+- browser + version,
+- expected vs actual behavior.