css3 transition, css3 transform effect, contact form using html and css, fancy contact form, best accordian using css, beautiful accordian using css, accordian without jquery, side navigation using css, side navigation, jquery accordian, css accordian, smooth transition effect for accordian, accordian like radio button effect. Many Variations of css-only accordion. And most of them are implemented using :target pseudo-class. The problem behind :target is we can not close the content areas again or we can perform it mupltipel. But by using hidden checkboxes, we can control the opening and closing.