CSS implementation of Apple-style continuous curvature squircle corners

On 2026-11-06 at 11:30, the Chinese developer platform Juejin published an article titled "Implementing Apple-Style Continuous-Curvature Rounded Corners (Squircle) with CSS". It walks through the mechanics of a continuous-curvature rounded-corner solution built on the mathematical n=4 superellipse, explaining why typical border-radius corners feel visually stiff: straight segments meet circular arcs where curvature abruptly jumps. Apple's visual language, as described in the piece, relies on a squircle whose curvature transitions smoothly, matching the n=4 superellipse formula rather than a simple circle-corner composite.

Beyond the theory, the article provides runnable CSS and SVG comparison code, allowing readers to see the two approaches side by side in a page. A closing section teaches how to phrase the same requirement to AI coding assistants so they can generate the effect from a prompt. This is the only corresponding report in the coverage window reviewed here.

No follow-up developments were found in the material: details such as how widely the technique is being adopted, browser-specific behaviors for the underlying path solutions, or performance comparisons against rasterized assets were left unaddressed beyond the code sample provided in the article.