CSS中的选项卡菜单——如何设置活动选项卡

So I have a tab menu written in CSS. It works fine, but there's one problem - all tabs are not active until I click on one of them. And I'd like, for example, first tab to be active just when I load the homepage, so I can read a content that's in the tab, not needing to click on it to read it.So I have a tab menu written in CSS. It works f