Web features we might not know

Dialog

Container Query

Color Mix

:focus-visible

accessibility friendly way handle focus for form inputs and buttons.

.btn:focus-visible {
  outline: 1px solid bisque;
}

.btn:focus:not(:focus-visible) {
  outline: none;
}

Array Last Element

arr.at(-1); // the last element

Deep Clone

const newObj = structuredClone(oldObj);