1、实现尖角符号。
这是内联inline-block标签独有的特性。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.a{
border-top:30px solid #000000 ;
border-bottom: 30px solid #2c78d5;
border-left:30px solid #1dd537 ;
border-right: 30px solid #ff3021;
display: inline-block;
}
.b{
border-top:30px solid #000000 ;
/*border-bottom: 30px solid #2c78d5;*/
border-left:30px solid #1dd537 ;
border-right: 30px solid #ff3021;
display: inline-block;
}
.c{
border: 30px solid transparent;
/*transparent为透明色*/
margin-top:20px ;
display: inline-block;
border-top:30px solid #000000 ;
}
.c:hover{
margin-top:-10px ;
border: 30px solid transparent;
border-bottom:30px solid #000000;
}
.bb{
border-top:30px solid #000000 ;
/*border-bottom: 30px solid #2c78d5;*/
border-left:30px solid #1dd537 ;
border-right: 30px solid #ff3021;
display: inline-block;
}
/*bb为自己想的方法,不需要改变自身的位置即可。*/
/*bb和b为长方形,其他为正方形*/
.bb:hover{
margin-top:15px ;
border: 0;
border-bottom: 30px solid #2c78d5;
border-left:30px solid #1dd537 ;
border-right: 30px solid #ff3021;
}
.a:hover{ }
</style>
</head>
<body>
<div class="a"></div>
<div class="b"></div>
<div class="bb"></div>
<div style="background-color: #ff3021;height: 70px">
<div class="c"></div>
</div>
</body>
</html>
鼠标临幸前:
鼠标临幸后:
2、实现输入框最后有小图标
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.login{
position: relative;
/*父级标签 position为 relative时,子标签才会根据父级标签定位。否则一级一级找,找不到就根据body定位*/
}
.login input{
width: 170px;
padding-right: 20px;
/*达到输入到R处就不增长的效果*/
height: 30px;
}
.ren{
position: absolute;
/*根据父标签 来定位。*/
top: 8px;
left: 180px;
}
</style>
</head>
<body>
<div class="login">
<input type="text">
<span class="ren">R</span>
</div>
</body>
</html>
输入前:
输入后:
文字不会超过“R”的位置,通过设置padding-right.
3、实现购物加减按钮
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.left{
float: left;
}
/*公用left*/
.w{
width: 96px;
border: 1px solid #ddd;
height: 22px;
}
.jia{
text-align: center;
line-height: 22px;
height: 22px;
width: 22px;
cursor: pointer;
/*鼠标放上去时,变成小手*/
}
.text{
height: 22px;
width: 50px;
padding: 0;
border: 0;
border-left: 1px solid #ddd ;
border-right: 1px solid #ddd ;
}
/*输入框左右2边各1px边框。*/
</style>
</head>
<body>
<div class="w">
<div class="jia left">+</div>
<input type="text" class="text left">
<div class="jia left">-</div>
</div>
</body>
</html>
4、页面布局
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
body{
margin: 0;
}
.top{
height: 48px;
width: 100%;
background-color: #7d7d7d;
}
.left{
position: absolute;
top:48px;
left: 0px;
width: 180px;
bottom: 0;
background-color: #1dd537;
}
.right{
position: absolute;
top:48px;
right: 0px;
left: 183px;
bottom: 0;
background-color: #1c6a9e;
overflow: auto;
/*如果内容超过自动长度,就会生成一个滚动条*/
}
</style>
</head>
<body>
<div class="top"> </div>
<div class="left">
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
</div>
<div class="right">
<h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1>
<h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1> <h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1><h1>333</h1>
</div>
</body>
</html>
这里最重要的就是:overflow: auto;如果内容超过自动长度,就会生成一个滚动条.
图上这个滚动条是属于蓝色背景的,非页面的滚动条
5、实现模态对话框
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
/*分为3层 1、最底层内容 2、一个遮罩层 3、对话框层*/
.zhezhao{
background-color: rgba(0,0,0,0.4);
position: fixed;
top:0;
left: 0;
bottom: 0;
right: 0;
z-index: 2;
/*优先级 比较低*/
}
.kuang{
width: 350px;
height: 250px;
/*5行*/
position: fixed;
top:50%;
left: 50%;
margin-left: -175px;
margin-top:-125px;
/*这5行 实现了真正的居中,margin的是框长宽的一半*/
background-color: white;
z-index: 3;
/*优先级 比较高 在最上边显示*/
}
</style>
</head>
<body>
<div><h1>Mr很大的龙</h1></div>
<div class="zhezhao">
</div>
<div class="kuang"></div>
</body>
</html>
6、伪类选择器补充
伪类选择器 可以对别的标签样式修改,例如:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.touch{
background-color: #1c6a9e;
width: 300px;
height: 300px;
overflow: hidden;
position: relative;
/*用来给子标签提供定位参考*/
}
.touch .content{
position: absolute;
top: 0;
left: 0;
right: 0;
bottom:0;
/*占满父级标签*/
background:rgba(0,0,0,0.6);
/*设置透明度*/
color: white;
text-align: center;
visibility: hidden;
/*隐藏起来*/
}
.touch:hover .content{
visibility: visible;
}
/*当touch被鼠标临幸时,修改content为显示*/
.touch .c1{
font-size: 32px;
/*padding: 60px 0;*/
line-height: 300px;
}
</style>
</head>
<body>
<div class="touch">
<div class="img"><img src="http://pic.iqshw.com/d/file/qita/weixin/2016/07/04/74af10abec5420f74c6c172dab6969a4.jpg"></div>
<div class="content c1">
大龙
</div>
</div>
</body>
</html>
鼠标临幸前:
鼠标临幸后:
7、css代码保护样式不被修改(优先级)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.a{
color: #ff3021 !important;
/*当一句css代码 后边跟!important的时候,下边的普通代码改变不了*/
font-size:50px ;
}
.b{
color: #1dd537 ;
/*试图改变颜色*/
}
</style>
</head>
<body>
<div class="a b">Mr很大的龙</div>
</body>
</html>
按照CSS执行顺序来说,文字应该是绿色,但文字为红色,因为被后边的“!important”保护
8、用position进行定位
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body> <div style="height: 2000px;width: 1000px">
<div style="width: 500px;height: 200px;margin: 0 auto;background-color: #2c78d5">
<!--有一定的宽度在设置margin:0 auto 可以让该标签左右居中-->
<div style="width: 300px;height: 100px;margin: 0 auto;background-color:#Fc78d5;position: relative">
<!--父级设置了relative-->
<div style="width: 30px;height: 30px;margin: 0 auto;background-color:#f7fc42;position:absolute;bottom: 0;left: 0"></div>
<!--子标签会根据最近的relative来进行定位-->
</div>
</div>
<div style="width: 50px;height: 50px;margin: 0 auto;background-color: #1dd537;position: fixed;top: 30px;right: 50px;">
<!--fixed 用来绝对定位,根据窗口来定位,滑动滚轮,位置也不会改变-->
</div>
</body>
</html>
当滚动条在最顶端时:
当滚动条在下边时:可以看到绿色块保持的位置是不变的。这就是position的 fixed属性