我想让导航栏粘在视口的顶部一旦用户滚动页面，但它不工作，我不知道为什么。如果你可以帮助，这是我的HTML和CSS代码:

.container { min-height: 300vh; } .nav-selections { text-transform: uppercase; letter-spacing: 5px; font: 18px "lato",sans-serif; display: inline-block; text-decoration: none; color: white; padding: 18px; float: right; margin-left: 50px; transition: 1.5s; } .nav-selections:hover{ transition: 1.5s; color: black; } ul { background-color: #B79b58; overflow: auto; } li { list-style-type: none; } <main class="container"> <nav style="position: sticky; position: -webkit-sticky;"> <ul align="left"> <li><a href="#/contact" class="nav-selections" style="margin-right:35px;">Contact</a></li> <li><a href="#/about" class="nav-selections">About</a></li> <li><a href="#/products" class="nav-selections">Products</a></li> <li><a href="#" class="nav-selections">Home</a></li> </ul> </nav> </main>