Semantic HTML and SEO Good HTML is not just markup — it is the contract between your content, search engines, assistive technologies, and the browser. Semantic HTML, correct metadata, and progressive enhancement make UI resilient, findable, and accessible by default. --- Semantic HTML5 Use the element that describes the content's meaning, not just its appearance. Document structure Headings One per page — the primary topic. Headings form an outline: do not skip levels ( → without ). Interactive elements Never use or as interactive elements without full ARIA annotation — and even then, prefer…