r-icon"></span>
				</button>
				<!-- 功能 -->
				<div class="collapse navbar-collapse" id="navbarSupportedContent">
					<ul class="navbar-nav mr-auto">
						<li class="nav-item ml-3 btn-group-vertical">
							<a class="nav-link" href="../../index.html">首页</a>
						</li>
						<li class="nav-item ml-3 btn-group-vertical">
							<a class="nav-link position-relative" href="../letter.html">消息<span class="badge badge-danger">12</span></a>
						</li>
						<li class="nav-item ml-3 bt