列的Bootstrap响应NavBar问题

Question

请帮忙。当我删除col-lg-3和col-lg-9类时，下面的代码工作正常。启用这些类后，当视口大小减小时，导航栏切换按钮不起作用。否则就行了。列类创建此问题的任何想法？

body
    .container-fluid
        .container
            nav.navbar.navbar-toggleable-md.navbar-light.bg-faded.row
                button.navbar-toggler.navbar-toggler-right(type='button' data-toggle='collapse' data-target='#navbarSupportedContent' aria-controls='navbarSupportedContent' aria-expanded='false' aria-label='Toggle navigation')
                    span.navbar-toggler-icon
                .navbar-brand.col-lg-3
                    img(src='img/main-logo.svg' height='60')
                .collapse.navbar-collapse#navbarSupportedContent.col-lg-9.nav-fill
                    ul.navbar-nav.ul-extension
                        li.nav-item.active
                            a.nav-link(href="#") Home
                        li.nav-item
                            a.nav-link(href='#') About
                        li.nav-item
                            a.nav-link(href='#') Services
                        li.nav-item
                            a.nav-link(href='#') Gallery
                        li.nav-item
                            a.nav-link(href='#') Contact