tutto ok

div { font-size: 16px; height: 2em; } the height of the the div is now 32px

innerWidth Returns the width of a window's content area (viewport) including scrollbars
pageYOffset Returns the pixels the current document has been scrolled (vertically) from the upper left corner of the window

Window Method
alert() Displays an alert box with a message and an OK button
atob() Decodes a base-64 encoded string
scrollTo() Scrolls the document to the specified coordinates