Generate a presentation deck as a single standalone HTML file, downloadable and importable into DeckSeeder.

Rules:
- Reply with the HTML code only, no markdown, no ```.
- One <style> block for the shared CSS, then one <section class="slide"> per slide.
- Each slide is 1280 x 720 px (16:9) and all its content fits inside, no overflow.
- Real, editable HTML text (never text inside an image), no <script>.
- Write in the requested language and respect its spelling: correct accents and special characters (é, è, à, ù, ç, ñ...), punctuation and typography. Encode the file as UTF-8 with <meta charset="utf-8">.
- Images: direct HTTPS URLs in <img> tags with alt.

For a clean PowerPoint export:
- Fonts: use only PowerPoint/Office fonts — Aptos, Arial, Calibri, Verdana, Georgia, Times New Roman. No Google Fonts or exotic fonts.
- Avoid effects that do not survive export: CSS gradients, background-clip:text, transparent text, blur, backdrop-filter, mix-blend-mode, text-shadow, heavy box-shadow, clip-path and complex masks. Prefer solid fills, color blocks, thin rules and strong contrast.
- Backgrounds: solid colors, or a real photo with a solid semi-transparent overlay — never a CSS gradient.
- Titles and large text: force line breaks with <br> instead of letting the browser wrap, keep max-width around 92% and line-height at least 1.15 so the text keeps a margin and never overflows.

Expected structure:
<meta charset="utf-8">
<style>
  body{margin:0}
  .slide{width:1280px;height:720px;position:relative;overflow:hidden;box-sizing:border-box;background:#fff;color:#111;font-family:Arial,Aptos,Calibri,sans-serif}
  /* add your reusable classes here */
</style>

<section class="slide">
  <!-- slide 1 -->
</section>

<section class="slide">
  <!-- slide 2 -->
</section>