CSS corner-top-right-shape Property

The corner-top-right-shape property controls the geometric outline applied specifically to the top‑right corner of a box, letting authors alter that single corner independently from the others. Rather than being limited to a simple radius, it can express a variety of corner treatments - from gentle rounding to sharp chamfers, inward notches, or more complex fitted curves - that change how the box’s edge is painted and how content is visually framed. Because it targets one corner only, it’s especially useful when you want asymmetry or a distinctive accent on a single edge without altering the rest of the element’s border geometry.

In painting and layout terms, the property determines the clip and bevel applied to that corner, so it affects where borders and backgrounds are drawn and how overflow is handled at that corner. It is designed to interoperate with general corner shaping mechanisms such as border-radius and with explicit outline/clipping primitives like clip-path, allowing authors to combine precise corner shaping with broader shape masking or complex element silhouettes. Where both this corner-specific shape and a more global corner rule exist, implementations resolve them in a predictable composition order so authors can layer effects (for example, applying a subtle global rounding with a pronounced top-right notch).

From a practical perspective, the property is a tool for visual refinement and interaction design: it can improve legibility by shaping how text and images sit near a corner, create affordances for clickable controls, and add distinctive branding flourishes to cards, badges, and containers. It is amenable to transitions and motion - animating the corner shape can provide subtle micro‑interactions - and should be considered alongside painting properties and shadowing to preserve optical balance. When authoring, consider how the corner’s geometry interacts with content overflow, hit-testing, and any masks or compositing that affect the element so the visual intention matches the element’s interactive behavior.