[eiserv]

The playground now uses a shared neutral design with direct shape comparison, controls, and an enlarged corner. The README is shorter, with detailed integration and migration guidance in a separate document. New screenshots include semi-transparent shadows and explicit display widths of 640 and 440 pixels. Five compact badges show the npm version, CI status, monthly downloads, included TypeScript types, and MIT license. npm run screenshots regenerates the images.

The code changes address specific lifecycle and compatibility issues. Shared DOM and React measurement handles vertical and sideways writing modes, older ResizeObserver size objects, and startup/window-resize fallback measurement. React rebinds when as changes. Later inline style changes, removed properties, and priorities survive redraw and cleanup. The shadow parser preserves modern and nested CSS color functions, and fully contracted shadows no longer cause geometry errors.

A new dependency-free squircles/svelte action supports reactive options and cleanup. A compiled Svelte example demonstrates both the action and modern attachments; the integration guide also includes Vue 3 usage through the DOM entry point. Public API names remain compatible. Documentation, code comments, error messages, examples, test descriptions, playground labels, and screenshots are in English.

Validation:

• npm run check: type checking, 40 Node tests, and npm package-content verification passed.
• npm run test:browser: 11 Chromium tests passed, covering lifecycle cleanup, inline changes, writing modes, ResizeObserver fallback, React host changes, Svelte actions and attachments, mobile layout, and idle rendering.
• Playground, React, and Svelte layouts checked at 320, 375, 768, and 1280 pixels without horizontal overflow.
• npm run screenshots and npm run visual:fixture succeeded; README images retain transparent margins and semi-transparent shadows.
• All five badge endpoints verified successfully.
• CI includes Node 20, 22, and 24 checks plus a separate Linux Chromium job.

Without ResizeObserver, fallback measurement only captures startup and window resize; other layout changes require a polyfill. Rendering limits are documented in the architecture and integration guides.