The CSS box-shadow property paints one or more shadows around an element without changing document layout. ShadowStack exposes only values that appear in the copied declaration, so the browser preview and source remain directly comparable. Each layer keeps its explicit paint order, inset state, four pixel lengths, hexadecimal colour and opacity.

Combine a contact shadow and ambient shadow

Use a first layer at 0 px, 4 px, 10 px, -4 px with #0F172A at 30 percent. Add a second layer at 0 px, 18 px, 36 px, -12 px with the same colour at 18 percent. Keep the smaller contact shadow first so it is painted above the broad ambient shadow. The two explicit layers separate near-edge definition from distant softness and are easier to tune than one extreme blur. Move the second layer up and back down to confirm that only list order changes, then copy the final comma-separated declaration.

Reduce layers before adding more

Evaluate the two-layer result against the actual surface and neighbouring components before adding another layer. Remove any layer whose contribution is not visible at ordinary size. More layers do not automatically create more realistic depth, and each additional value increases review and maintenance cost. Keep offsets aligned with the intended visual direction, use opacity rather than pure black intensity for restraint, and document the accepted declaration beside the component that owns it.

Verify the CSS in its real component

ShadowStack renders the copied declaration with the current browser engine, but the preview is not a compatibility or accessibility certificate. Paste the property into the intended component and test every supported browser, responsive width, background and overflow container. A broad blur may be clipped by an ancestor and an inset shadow may cover content or focus indicators. Inspect keyboard focus at every state, measure text and control contrast with a dedicated tool, and retain a usable border or other non-shadow distinction when the interface depends on clear boundaries. The capsule stores no presets or history, so keep accepted CSS in your own source-controlled stylesheet before reloading.