HTML

Writes, reviews, and fixes HTML markup: semantic structure, forms, accessibility, the document head, media and embeds. Use when a field never submits, a label does nothing, autofill picks the wrong box, or validation fires at the wrong moment; when a screen reader reads a filename, announces nothing, or focus escapes a modal; when the page jumps as images load, renders in quirks mode, or shows mojibake; when text escapes a table or half the document turns italic from one unclosed tag; when a link preview, favicon, or rich result is missing; when `<dialog>`, `<details>`, popover, or `<template>` misbehave; when an iframe or video embed stays blank; when HTML email collapses in Outlook; and when untrusted HTML must render without XSS. Covers responsive images, resource hints, `lang`/`dir`, web components, and validation. Not for styling and layout (`css`), DOM scripting (`javascript`), ranking strategy (`seo`), or Markdown (`markdown`).