update

files/en-us/web/api/document/fullscreenchange_event/index.md

@@ -6,9 +6,9 @@ page-type: web-api-event
 browser-compat: api.Document.fullscreenchange_event
 ---
 
-{{APIRef}}
+{{APIRef("Fullscreen API")}}
 
-The `fullscreenchange` event is fired immediately after the browser switches into or out of fullscreen mode.
+The **`fullscreenchange`** event is fired immediately after the browser switches into or out of fullscreen mode.
 
 The event is sent to the `Element` that is transitioning into or out of fullscreen mode, and this event then bubbles up to the `Document`.
 
@@ -38,9 +38,9 @@ In this example, a handler for the `fullscreenchange` event is added to the {{do
 
 If the user clicks on the "Toggle Fullscreen Mode" button, the `click` handler will toggle fullscreen mode for the `div`. If `document.fullscreenElement` has a value it will exit fullscreen mode. If not, the div will be placed into fullscreen mode.
 
-Remember that by the time the `fullscreenchange` event is handled, the status of the element has already changed. So if the change is to fullscreen mode, `document.fullscreenElement` will point to the element that is now in fullscreen mode. On the other hand, if `document.fullscreenElement` is null, fullscreen mode has been canceled.
+Remember that by the time the `fullscreenchange` event is handled, the status of the element has already changed. So if the change is to fullscreen mode, `document.fullscreenElement` will point to the element that is now in fullscreen mode. On the other hand, if `document.fullscreenElement` is `null`, fullscreen mode has been canceled.
 
-What that means to the example code is that, if an element is currently in fullscreen mode, the `fullscreenchange` handler logs the `id` of the fullscreen element to the console. If `document.fullscreenElement` is null, the code logs a message that the change is to leave fullscreen mode.
+What that means to the example code is that, if an element is currently in fullscreen mode, the `fullscreenchange` handler logs the `id` of the fullscreen element to the console. If `document.fullscreenElement` is `null`, the code logs a message that the change is to leave fullscreen mode.
 
 #### HTML
 

files/en-us/web/api/document/fullscreenerror_event/index.md

@@ -6,9 +6,9 @@ page-type: web-api-event
 browser-compat: api.Document.fullscreenerror_event
 ---
 
-{{APIRef}}
+{{APIRef("Fullscreen API")}}
 
-The `fullscreenerror` event is fired when the browser cannot switch to fullscreen mode.
+The **`fullscreenerror`** event is fired when the browser cannot switch to fullscreen mode.
 
 As with the [`fullscreenchange` event](/en-US/docs/Web/API/Document/fullscreenchange_event), two `fullscreenerror` events are fired; the first is sent to the {{domxref("Element")}} which failed to change modes, and the second is sent to the {{domxref("Document")}} which owns that element.
 

files/en-us/web/api/element/fullscreenchange_event/index.md

@@ -6,9 +6,9 @@ page-type: web-api-event
 browser-compat: api.Element.fullscreenchange_event
 ---
 
-{{APIRef}}
+{{APIRef("Fullscreen API")}}
 
-The `fullscreenchange` event is fired immediately after an {{domxref("Element")}} switches into or out of fullscreen mode.
+The **`fullscreenchange`** event is fired immediately after an {{domxref("Element")}} switches into or out of fullscreen mode.
 
 This event is sent to the `Element` which is transitioning into or out of fullscreen mode.
 
@@ -36,9 +36,9 @@ In this example, a handler for the `fullscreenchange` event is added to the elem
 
 If the user clicks on the "Toggle Fullscreen Mode" button, the `click` handler will toggle fullscreen mode for the `div`. If `document.fullscreenElement` has a value it will exit fullscreen mode. If not, the div will be placed into fullscreen mode.
 
-Remember that by the time the `fullscreenchange` event is handled, the status of the element has already changed. So if the change is to fullscreen mode, `document.fullscreenElement` will point to the element that is now in fullscreen mode. On the other hand, if `document.fullscreenElement` is null, fullscreen mode has been canceled.
+Remember that by the time the `fullscreenchange` event is handled, the status of the element has already changed. So if the change is to fullscreen mode, `document.fullscreenElement` will point to the element that is now in fullscreen mode. On the other hand, if `document.fullscreenElement` is `null`, fullscreen mode has been canceled.
 
-What that means to the example code is that, if an element is currently in fullscreen mode, the `fullscreenchange` handler logs the `id` of the fullscreen element to the console. If `document.fullscreenElement` is null, the code logs a message that the change is to leave fullscreen mode.
+What that means to the example code is that, if an element is currently in fullscreen mode, the `fullscreenchange` handler logs the `id` of the fullscreen element to the console. If `document.fullscreenElement` is `null`, the code logs a message that the change is to leave fullscreen mode.
 
 ### HTML
 

files/en-us/web/api/element/fullscreenerror_event/index.md

@@ -6,9 +6,9 @@ page-type: web-api-event
 browser-compat: api.Element.fullscreenerror_event
 ---
 
-{{APIRef}}
+{{APIRef("Fullscreen API")}}
 
-The `fullscreenerror` event is fired when the browser cannot switch to fullscreen mode.
+The **`fullscreenerror`** event is fired when the browser cannot switch to fullscreen mode.
 
 As with the [`fullscreenchange` event](/en-US/docs/Web/API/Element/fullscreenchange_event), two `fullscreenerror` events are fired; the first is sent to the {{domxref("Element")}} which failed to change modes, and the second is sent to the {{domxref("Document")}} which owns that element.