如何在我的网页加载时显示加载内容，并在页面完全加载时隐藏此内容？

I made a nice loading animation with CSS and JS/JQuery. It features a white line turning around into a coloured circle. It works perfectly fine in a seperated html, but now i wanna include it on my webpage. There is a general script linked to the HTML called script.js. The script for making the animation work is called animation.js. This is my code so far:I made a nice loading animation with CSS and JS