温温酱
html, body {
font-family: Arial, Helvetica, sans-serif;}/* define a fixed width for the entire menu */.navigation {
width: 150px;}/* reset our lists to remove bullet points and padding */.mainmenu, .submenu {
list-style: none;
padding: 0;
margin: 0;}/* make ALL links (main and submenu) have padding and background color */.mainmenu a {
display: block;
background-color: #CCC;
text-decoration: none;
padding: 10px;
color: #000;}/* add hover behaviour */.mainmenu a:hover {
background-color: #C5C5C5;}/* when hovering over a .mainmenu item,
display the submenu inside it.
we're changing the submenu's max-height from 0 to 200px;
*/.mainmenu li:hover .submenu {
display: block;
max-height: 200px;}/*
we now overwrite the background-color for .submenu links only.
CSS reads down the page, so code at the bottom will overwrite the code at the top.
*/.submenu a {
background-color: #999;}/* hover behaviour for links inside .submenu */.submenu a:hover {
background-color: #666;}/* this is the initial state of all submenus.
we set it to max-height: 0, and hide the overflowed content.
*/.submenu {
overflow: hidden;
max-height: 0;
-webkit-transition: all 0.5s ease-out;}<html><body><head><link rel="stylesheet" type="css/text" href="nav.css"></head></body><nav class="navigation">
<ul class="mainmenu">
<li><a href="">Home</a></li>
<li><a href="">About</a></li>
<li><a href="">Products</a>
<ul class="submenu">
<li><a href="">Tops</a></li>
<li><a href="">Bottoms</a></li>
<li><a href="">Footwear</a></li>
</ul>
</li>
<li><a href="">Contact us</a></li>
</ul></nav>