border-(top,right,bottom,left)-style: 边框样式
border-(top,right,bottom,left)-width: 边框宽度
border-(top,right,bottom,left)-color: 边框颜色
clear 指定不允许元素周围有浮动元素。
float 指定一个盒子(元素)是否可以浮动。
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #333;
}
li {
float: left;
border-right:1px solid #bbb;
}
li:last-child {
border-right: none;
}
li a {
display: block;
color: white;
text-align: center;
padding: 14px 16px;
text-decoration: none;
}
li a:hover:not(.active) {
background-color: #111;
}
.active {
background-color: #4CAF50;
}
</style>
</head>
<body>
<ul>
<li><a class="active" href="#home">主页</a></li>
<li><a href="#news">新闻</a></li>
<li><a href="#contact">联系</a></li>
<li style="float:right"><a href="#about">关于</a></li>
</ul>
</body>
</html>
<html>
<head>
<title>下拉菜单实例</title>
<meta charset="utf-8">
<style>
.dropbtn {
background-color: #4CAF50;
color: white;
padding: 16px;
font-size: 16px;
border: none;
cursor: pointer;
}
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
}
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
}
.dropdown-content a:hover {background-color: #f1f1f1}
.dropdown:hover .dropdown-content {
display: block;
}
.dropdown:hover .dropbtn {
background-color: #3e8e41;
}
</style>
</head>
<body>
<h2>下拉菜单</h2>
<p>鼠标移动到按钮上打开下拉菜单。</p>
<div class="dropdown">
<button class="dropbtn">下拉菜单</button>
<div class="dropdown-content">
<a href="//www.runoob.com">菜鸟教程 1</a>
<a href="//www.runoob.com">菜鸟教程 2</a>
<a href="//www.runoob.com">菜鸟教程 3</a>
</div>
</div>
</body>
</html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<style>
.tooltip {
position: relative;
display: inline-block;
border-bottom: 1px dotted black;
}
.tooltip .tooltiptext {
visibility: hidden;
width: 120px;
background-color: black;
color: #fff;
text-align: center;
border-radius: 6px;
padding: 5px 0;
/* 定位 */
position: absolute;
z-index: 1;
}
.tooltip:hover .tooltiptext {
visibility: visible;
}
</style>
<body style="text-align:center;">
<div class="tooltip">鼠标移动到这
<span class="tooltiptext">提示文本</span>
</div>
</body>
</html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
<style>
div.img {
margin: 5px;
border: 1px solid #ccc;
float: left;
width: 180px;
}
div.img:hover {
border: 1px solid #777;
}
div.img img {
width: 100%;
height: auto;
}
div.desc {
padding: 15px;
text-align: center;
}
</style>
</head>
<body>
<div class="responsive">
<div class="img">
<a target="_blank" href="//static.runoob.com/images/demo/demo1.jpg">
<img src="//static.runoob.com/images/demo/demo1.jpg" alt="图片文本描述" width="300" height="200">
</a>
<div class="desc">这里添加图片文本描述</div>
</div>
</div>
</body>
</html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<style>
input[type=text], select {
width: 100%;
padding: 12px 20px;
margin: 8px 0;
display: inline-block;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box;
}
input[type=submit] {
width: 100%;
background-color: #4CAF50;
color: white;
padding: 14px 20px;
margin: 8px 0;
border: none;
border-radius: 4px;
cursor: pointer;
}
input[type=submit]:hover {
background-color: #45a049;
}
div {
border-radius: 5px;
background-color: #f2f2f2;
padding: 20px;
}
</style>
<body>
<h3>使用 CSS 来渲染 HTML 的表单元素</h3>
<div>
<form action="/action_page.php">
<label for="fname">First Name</label>
<input type="text" id="fname" name="firstname" placeholder="Your name..">
<label for="lname">Last Name</label>
<input type="text" id="lname" name="lastname" placeholder="Your last name..">
<label for="country">Country</label>
<select id="country" name="country">
<option value="australia">Australia</option>
<option value="canada">Canada</option>
<option value="usa">USA</option>
</select>
<input type="submit" value="Submit">
</form>
</div>
</body>
</html>