Animated Accordion

Why it works:

Default accordions feel like form widgets. This one has enough hand-tuned motion (the rail, the icon, the height transition) that it reads as part of the design instead of a stock component, without the bundle cost of a motion library.

Under the hood:

- Heights animate from a measured pixel value back to zero, so the transition stays smooth at any content length.

- The plus icon is two SVG strokes that rotate independently, turning from a `+` into a horizontal bar.

- When two or more items are open, a vertical line draws between them along the accent rail.

Best for:

- FAQ sections and pricing pages

- Documentation, help centers, and onboarding

- Agency portfolios and studio sites

- Premium SaaS and marketing pages

- Product feature lists

Controls:

- Items: array of `{ title, body }` pairs

- Accent: glow and active-state color

- Mode: single or multiple open at once

- Default Open: index of the item that starts open (-1 for none)

- Title Size, Body Size: typography

- Title Color, Body Color, Muted: text palette

- Border: divider line color

- Row Gap: spacing between items

Built for production:

Pure CSS transitions, no animation libraries. Keyboard accessible with `aria-expanded` and `aria-controls` wired up. Respects `prefers-reduced-motion` (clicks still work, transitions soften). Responsive at any width.