example:
<details class="menu" open> <summary>menu</summary> <ul> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> </ul> </details>
You can define related styles with css
.menu summary { height: 40px; line-height: 40px; text-indent: 10px; outline: none; font-weight: 700; border-top: 1px solid #ddd; background: -webkit-gradient(linear, left top, left bottom, color-stop(0, #FEFEFE), color-stop(1, #CCCCCC)); cursor: pointer; } .menu ul { padding: 10px 0; margin: 0; } .menu ul li { list-style: none; text-indent: 25px; height: 30px; line-height: 30px; } .menu ul li a { display: block; color: #666; text-decoration: none; }
<! doctype html> <html> <head> <meta charset="utf-8"> <title>Untitled document</title> <style> * { margin: 0; padding: 0; } a { text-decoration: none; } #conter { width: 1000px; margin: auto; } #help-left { width: 200px; font-family: 'microsoft YaHei'; float: left; } .menu { border-left: 1px solid #ccc; border-right: 1px solid #ccc; } .menu:last-child { border-bottom: 1px solid #ccc; } .menu summary { height: 40px; line-height: 40px; text-indent: 10px; outline: none; font-size: 14px; font-weight: 700; border-top: 1px solid #ddd; background: -webkit-gradient(linear, left top, left bottom, color-stop(0, #FEFEFE), color-stop(1, #CCCCCC)); cursor: pointer; } .menu summary::-webkit-details-marker { display: none; } /*Images or characters are available. If images are used, set the value of content to null*/ .menu summary:before { content: "+"; /*background: url(../Images/right.png) no-repeat center center;*/ /*Picture when stowed*/ display: inline-block; width: 16px; height: 16px; margin-right: 10px; font-size: 18px; font-weight: 700; } .menu[open] summary:before { content: "-"; /*background: url(../Images/down.png) no-repeat center center;*/ /*Picture when expanded*/ } .menu ul { padding: 10px 0; } .menu ul li { list-style: none; text-indent: 25px; font-size: 12px; height: 30px; line-height: 30px; } .menu ul li a { display: block; color: #666; } .menu ul li a:hover { text-decoration: underline; } </style> </head> <body> <section id="conter"> <section id="help-left"> <details class="menu" open> <summary>Menu 1</summary> <ul> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> </ul> </details> <details class="menu" open> <summary>Menu 2</summary> <ul> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> </ul> </details> <details class="menu" open> <summary>Menu 3</summary> <ul> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> </ul> </details> <details class="menu" open> <summary>Menu 4</summary> <ul> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> <li><a href="#">Submenu</a></li> </ul> </details> </section> </section> </body> </html>