The contain CSS property indicates that an element and its contents are, as much as possible, independent from the rest of the document tree.
Containment enables isolating a subsection of the DOM, providing performance benefits by limiting calculations of layout, style, paint, size, or any combination to a DOM subtree rather than the entire page. Containment can also be used to scope CSS counters and quotes....standard values or one of the two shorthand values. Changes to... paint , strict or content values for this property creates:...