<!DOCTYPE html> <html lang="cs"> <head> <meta charset="utf-8" /> <title>Postřeh</title> <style> body {background-color: red} #vysledek { font-size: 200%; font-weight: bold; position: absolute; left: 50%; top: 50%; -webkit-transform: translate(-50%, -50%); transform: translate(-50%, -50%); } </style> <script> /* <![CDATA[ */ /* Sem prijde javascript kod */ let casA let casB setTimeout( function(){ casA = new Date() document.body.style.backgroundColor = "green" }, 5000 + 5000 * Math.random()) function klavesa(event){ if(event.code == 'Space'){ casB = new Date() document.getElementById('vysledek').innerHTML = (casB - casA)+"ms" } } document.addEventListener("keydown", klavesa); /* ]]> */ </script> </head> <body> <div id="vysledek"></div> </body> </html>