Subresource Integrity (SRI) is a security feature that enables browsers to verify that resources they fetch (for example, from a CDN) are delivered without unexpected manipulation. It works by allowing you to provide a cryptographic hash that a fetched resource must match.| developer.mozilla.org
The cascade is an algorithm that defines how user agents combine property values originating from different sources. The cascade defines the origin and layer that takes precedence when declarations in more than one origin, cascade layer, or @scope block set a value for a property on an element.| developer.mozilla.org
The @starting-style CSS at-rule is used to define starting values for properties set on an element that you want to transition from when the element receives its first style update, i.e., when an element is first displayed on a previously loaded page.| developer.mozilla.org
This article explains how to create fully-customized| developer.mozilla.org
The Reflect.set() static method is like the property accessor and assignment syntax, but as a function.| developer.mozilla.org
The spread (...) syntax allows an iterable, such as an array or string, to be expanded in places where zero or more arguments (for function calls) or elements (for array literals) are expected. In an object literal, the spread syntax enumerates the properties of an object and adds the key-value pairs to the object being created.| developer.mozilla.org
The Object.assign() static method copies all enumerable own properties from one or more source objects to a target object. It returns the modified target object.| developer.mozilla.org
The slice() method of Array instances returns a shallow copy of a portion of an array into a new array object selected from start to end (end not included) where start and end represent the index of items in that array. The original array will not be modified.| developer.mozilla.org
The Array.from() static method creates a new, shallow-copied Array instance from an iterable or array-like object.| developer.mozilla.org
The concat() method of Array instances is used to merge two or more arrays. This method does not change the existing arrays, but instead returns a new array.| developer.mozilla.org
The CSS nesting module allows you to write your stylesheets so that they are easier to read, more modular, and more maintainable. As you are not constantly repeating selectors, the file size can also be reduced.| developer.mozilla.org
Background scripts or a background page enable you to monitor and react to events in the browser, such as navigating to a new page, removing a bookmark, or closing a tab.| developer.mozilla.org
The handler.set() method is a trap for the [[Set]] object internal method, which is used by operations such as using property accessors to set a property's value.| developer.mozilla.org
