* { margin:0; padding:0; list-style:none; } #box { width:200px; height:200px; border:2px solid red; margin:50px auto; border-radius:100px; position:relative; } /*#s { width:30px; height:30px; background:red; position:absolute; top:0; margin-top:-15px; left:50%; margin-left:-15px; border-radius:50%; } */ span { width:30px; height:30px; background:red; position:absolute; top:0; margin-top:-15px; left:50%; margin-left:-15px; border-radius:50%; }
初始化时,圆上只有一个实心小圆,点击后,远着圆圈生成若干个小圆