Build a single, self-contained HTML file (one file: inline and inline , no build step, no frameworks, no external JS/CSS libraries) containing ONE full-viewport hero section for an ocean-conservation nonprofit called "OceanPulse". ===================================================================== 1. GLOBAL SETUP ===================================================================== - , lang="en". - - OceanPulse — Saving Oceans, Uniting The Coastline - Font: Plus Jakarta Sans from Google Fonts, weights 400;500;600;700, with preconnect to fonts.googleapis.com and fonts.gstatic.com (crossorigin): https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700&display=swap Body stack: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif. -webkit-font-smoothing:antialiased; img,video { display:block; max-width:100% }. - body.nav-open { overflow:hidden } (scroll lock while the menu is open). CSS custom properties on :root: --ink:#111417 --muted:#6b7178 --bg:#ffffff --radius-card:26px --pad:clamp(20px, 2.2vw, 34px) --ease-out:cubic-bezier(.16,1,.3,1) --ease-in:cubic-bezier(.7,0,.84,0) --stagger:72ms --nature-img:url("https://images.higgs.ai/?default=1&output=webp&url=https%3A%2F%2Fd8j0ntlcm91z4.cloudfront.net%2Fuser_38xzZboKViGWJOttwIXH07lWA1P%2Fhf_20260831_224622_4eeb9d43-9e46-4483-9530-1eb4ef4c942d.png&w=1920&q=85") ===================================================================== 2. EXACT ASSET URLS (use ve
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