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WASM demo

<span class="markdown prose dark:prose-invert contents"><span class="paragraph">This page is rendered with <code>mode: wasm</code>. Marimo's runtime loads
in your browser via Pyodide on first paint (one-time download
~30 MB; subsequent visits are cached). Once loaded, the slider
below is <strong>truly reactive</strong> — no precomputed lookup table, no
caps. Drag continuously and the cell below recomputes Python
on each input.</span>
<span class="paragraph">Compare this with the <a href="precompute_demo.md">Static reactivity demo</a>,
which precomputes a fixed grid of values at build time and
ships zero Python at runtime. Both approaches have their place:</span>
<ul>
<li><strong>Static + precompute</strong>: instant first paint, works offline,
  tiny page, but limited to a fixed value grid declared at
  author time. Good default.</li>
<li><strong>WASM</strong>: full Python in the browser, every cell reactive,
  continuous sliders work, no caps. But heavy first paint and
  requires the user's browser to download Pyodide.</li>
</ul>
<span class="paragraph">Use <code>mode: wasm</code> per-page (in <code>book.yml</code>'s <code>toc</code> entry) for
chapters that genuinely need full reactivity. Leave the rest
static for fast loads.</span></span>

<span class="markdown prose dark:prose-invert contents"><span class="paragraph">Sum of 1..10 computed live:</span>
<ul>
<li>Loop: <strong>55</strong></li>
<li>Closed form (n·(n+1)/2): <strong>55</strong></li>
</ul></span>