$% This is a comment - it won't appear in the preview $ <title>Upmath Playground</title> <adjust bgcolor="#0a0a0f" style="color: #e0e0e0; padding: 2rem;"> # Hello, Upmath Playground Write **markdown** with $KaTeX$ math support, GFM tables, task lists, and a `<>...</>` spacer. --- ## Display Math $$ E = mc^2 $$ $$ \int_{-\infty}^{\infty} e^{-x^2}\,dx = \sqrt{\pi} $$ ## Inline Math The quadratic formula: $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$ Euler's identity: $e^{i\pi} + 1 = 0$ ## Spacer Item A<>big gap</>Item B — the `<>...</>` inserts a wide invisible space. ## Task List - [x] Write the parser - [x] Add KaTeX support - [ ] Add more features - [ ] Deploy to production ## GFM Table | Command | Syntax | Renders | |---------|--------|---------| | Display math | `$$...$$` | Centered block | | Inline math | `$...$` | Inline formula | | Spacer | `<>...</>` | Wide invisible space | ## Markdown - **Bold** and *italic* and ~~strikethrough~~ - [Links](https://example.com) - `inline code` and ``` code blocks ``` ### HTML Elements <font color="#00f0ff">This text is cyan via the font tag.</font> <button style="background:#00f0ff; color:#000; border:0; padding:8px 16px; border-radius:6px; font-weight:600; cursor:pointer;"> Neon Button </button> > Blockquote with a splash of style. </adjust>

Hello, Upmath Playground

Write markdown with $KaTeX$ math support, GFM tables, task lists, and a <span style="font-size:2em;visibility:hidden;display:inline-block">a</span> spacer.

Display Math

E = mc^2

\int_{-\infty}^{\infty} e^{-x^2}\,dx = \sqrt{\pi}

Inline Math

The quadratic formula: $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

Euler's identity: $e^{i\pi} + 1 = 0$

Spacer

Item AaItem B — the <span style="font-size:2em;visibility:hidden;display:inline-block">a</span> inserts a wide invisible space.

Task List

Write the parser
Add KaTeX support
Add more features
Deploy to production

GFM Table

Command	Syntax	Renders
Display math	`<!--KATEX_PH_2-->`	Centered block
Inline math	`<!--KATEX_PH_6-->`	Inline formula
Spacer	`<span style="font-size:2em;visibility:hidden;display:inline-block">a</span>`	Wide invisible space

Markdown

Bold and italic and ~~strikethrough~~
Links
inline code and ```
code blocks


### HTML Elements

<font color="#00f0ff">This text is cyan via the font tag.</font>

<button
  style="background:#00f0ff; color:#000; border:0; padding:8px 16px; border-radius:6px; font-weight:600; cursor:pointer;">
  Neon Button
</button>

> Blockquote with a splash of style.