A clean, single-file HTML sample

Semantic markup, responsive CSS with custom properties, and a dash of vanilla JavaScript — no frameworks, no build step, no external requests. Copy it, edit it, ship it.

📐 Responsive

Fluid grids and clamp() typography adapt from phone to desktop.

🎨 Themeable

All colors live in CSS variables at the top — change one to restyle all.

⚡ Zero deps

One file, no libraries, no network calls. Works offline out of the box.

JavaScript demo — click the button:

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