offcanvas.css

@-ms-viewport     { width: device-width; }

@-o-viewport      { width: device-width; }

@viewport         { width: device-width; }

/*

 * Style tweaks

 * --------------------------------------------------

 */

html,body {overflow-x: hidden; /* Prevent scroll on narrow devices */}

body {padding-top: 70px;}

footer {padding: 30px 0;}

/*

 * Off Canvas

 * --------------------------------------------------

 */

@media screen and (max-width: 767px) {

  .row-offcanvas {position: relative;-webkit-transition: all .25s ease-out;-o-transition: all .25s ease-out;transition: all .25s ease-out;}

  .row-offcanvas-right {right: 0;}

  .row-offcanvas-left {left: 0;}

  .row-offcanvas-right

  .sidebar-offcanvas {right: -50%; /* 6 columns */}

  .row-offcanvas-left

  .sidebar-offcanvas {left: -50%; /* 6 columns */}

  .row-offcanvas-right.active {right: 50%; /* 6 columns */}

  .row-offcanvas-left.active {left: 50%; /* 6 columns */}

  .sidebar-offcanvas {position: absolute;top: 0;width: 50%; /* 6 columns */}

}

offcanvas.css没有找到

为什么点一下没有那个下拉导航呢

要设置button的点击事件的，网页地址  http://v3.bootcss.com/examples/offcanvas/ ，查看源代码，加入offcanvas.css和offcanvas.js就可以了，前面几个人都只答对了一部分

同问，为什么点一下没有那个下拉菜单呢

bootstrap组件作用