Bookmarklet to expand a YouTube embed iframe to fill the window (will collapse if used again)

yt-expand

javascript:(function()%7Bvar%20yt=document.querySelector('iframe%5Bsrc*=%22youtube.com/embed%22%5D'),ytExpanded=!!yt.dataset.iframeExpanded,ytStyle=yt.style;if(ytExpanded)%7Byt.style.cssText=yt.dataset.ytOldStyle;yt.removeAttribute('data-iframe-expanded');%7Delse%7Byt.dataset.ytOldStyle=ytStyle.cssText;yt.dataset.iframeExpanded=true;ytStyle.position='absolute';ytStyle.width='94%25';ytStyle.height='94%25';ytStyle.boxShadow='0%200%203em%20rgba(0,%200,%200,%20.8)';ytStyle.top='3%25';ytStyle.left='3%25';%7D%7D)();