within application toolbars, are slightly rounded rectangles with a light grey metallic appearance. These buttons appear darker and "pushed inward" when pressed. Window management controls appear in the top left corner of each window. These buttons are similar in style to standard aqua buttons, but are color-coded as a memory aid. From left to right, these are: "Close Window", shown in red; "Minimize Window", shown in yellow; and "Zoom", shown in green, which causes the window to resize to best fit its contents. Windows shell Buttons in Microsoft Windows are usually rectangular, with mildly rounded corners in Windows XP, Vista, and 7, with a return to form in Windows 11. In Windows 8, the buttons are rectangular with sharp corners. A button with active focus is shown with a black dotted line just inside the border of the button. In addition, more recent versions, the default button is shown with a blue border. In Windows Vista and Windows 7, the default button will slowly fade between its normal appearance and the blue border. Window management controls are in the upper right-hand corner of the application window, and, from left to right: "minimize" the window (causing it to disappear into the taskbar at the bottom of the screen); maximize the window (causing it to expand to cover the whole screen; if the window is already maximized, the button will restore it to its previous size and position); and close the window. Linux and other Unix-like systems The appearance and behavior of buttons in Linux and other Unix-like operating systems is defined primarily by which widget toolkit is being employed, the most popular being GTK and Qt, though other toolkits are used as well. The use of multiple toolkits can lead to less uniform look and feel across applications. Most widget toolkits also have theming capabilities, so there is no single standard appearance as there is with Mac OS and Windows. HTML Buttons appear as elements of HTML forms to carry out actions such as clearing user input or submitting the form contents to the server. Buttons specified in HTML may be rendered by web browsers in different ways, typically either using the native button appearance of the underlying OS, or by using a button definition from within the browser. Buttons may also be styled by the developer of the web site the form appears on by using cascading style sheets. HTML