article,aside,details,figure,figcaption,footer,header,hgroup,menu,nav,section,summary{display:block;}
dialog,figure{margin-top:1em;margin-bottom: 1em;}
figure{margin-left:40px;margin-right:40px;}
details{padding-left:40px;}
details>div{overflow:hidden;height:0;}
details.open>div,details[open]>div{overflow:auto;height:auto;}
details>summary:first-child{cursor:pointer;}
details>summary:first-child:before{content:'\25BA';float:left;margin-right:8px;}
details.open>summary:first-child:before,details[open]>summary:first-child:before{content:'\25BC';}
mark{background:yellow;color:black;}