本周内容：
day01
css
定位流：相对定位、绝对定位、固定定位
js
ECMAScript=》语法
BOM=》控制浏览器
day02
DOM=》控制文档内容的动态效果
案列
https://www.cnblogs.com/linhaifeng/articles/9472477.html#_label2
day03
jquery
bootstrap框架
1.相对定位
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
/*display: inline-block;*/
}
.box2 {
width: 200px;
height: 200px;
background-color: green;
/*position: relative;*/
/*top: 100px;*/
/*bottom: 10px;*/
/*left: 10px;*/
/*right: 10px;*/
/*margin-top: 10px;*/
/* display: inline-block;*/
}
.box3 {
/*width: 200px;*/
/*height: 200px;*/
background-color: blue;
/*display: inline-block;*/
}
img {
height: 50px;
position: relative;
top: 22px;
left: 10px;
}
input {
height: 50px;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box2"></div>
<div class="box3"></div>
<input type="text">
<img src="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1600660576985&di=2d70af39c234727def903cbdcc0d6e92&imgtype=0&src=http%3A%2F%2Fwww.zhuangjiba.com%2Fd%2Ffile%2Fhelp%2F2018%2F08%2Fcfdefaddb3f47d78f8c66a7de28720aa.png" alt="">
</body>
</html>
2.绝对定位
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
}
.box2 {
width: 200px;
height: 200px;
background-color: green;
position: absolute;
top: 50px;
left: 50px;
}
.box3 {
width: 300px;
height: 300px;
background-color: blue;
position: relative;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box3">
<div class="box2"></div>
</div>
</body>
</html>
练习
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
ul {
list-style: none;
}
ul>li {
float: left;
width: 100px;
height: 50px;
background-color: gray;
text-align: center;
line-height: 50px;
}
ul>li:hover {
background-color: green;
}
.bg {
background-image: url("代码/1.png");
background-repeat: no-repeat;
background-size: 30px;
background-position: right top;
}
ul>li:nth-child(4) {
position: relative;
}
img {
position: absolute;
width: 30px;
left: 30px;
top: -3px;
}
</style>
</head>
<body>
<ul>
<li>服装城</li>
<li>服装城</li>
<li>服装城</li>
<li>
服装城
<img src="1.png" alt="">
</li>
<li>服装城</li>
<li>服装城</li>
<li>服装城</li>
</ul>
<div style="width: 200px;height: 200px;background-color: red;clear: both">
asdfsafadsf
<p>哈哈哈</p>
</div>
</body>
</html>
2.绝对定位-以body首屏作为参考点
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
}
.box2 {
width: 2000px;
height: 200px;
background-color: green;
}
.box3 {
width: 300px;
height: 3000px;
background-color: blue;
position: relative;
}
span {
display: inline-block;
width: 100px;
height: 100px;
background-color: pink;
text-align: center;
line-height: 100px;
border-radius: 50%;
position: absolute;
bottom: 0;
right: 0;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box2"></div>
<div class="box3"></div>
<span>回到顶部</span>
</body>
</html>
3.绝对定位居中
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
}
.box2 {
width: 50px;
height: 50px;
background-color: green;
position: absolute;
left: 50%;
margin-left: -25px;
top: 50%;
margin-top: -25px;
}
.box3 {
width: 300px;
height: 300px;
background-color: blue;
position: relative;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box3">
<div class="box2"></div>
</div>
</body>
</html>
3.忽略父级的padding属性
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
}
.box2 {
width: 200px;
height: 200px;
background-color: green;
position: absolute;
top:10px;
left:10px;
}
.box3 {
width: 300px;
height: 300px;
background-color: blue;
position: relative;
padding: 50px;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box3">
<div class="box2"></div>
</div>
</body>
</html>
3.固定定位
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
}
.box2 {
width: 2000px;
height: 200px;
background-color: green;
}
.box3 {
width: 300px;
height: 3000px;
background-color: blue;
}
a {
width: 100px;
height: 100px;
background-color: pink;
text-align: center;
line-height: 100px;
border-radius: 50%;
position: fixed;
bottom: 0;
right: 0;
text-decoration: none;
}
</style>
</head>
<body>
<div class="box1"></div>
<div class="box2"></div>
<div class="box3"></div>
<a href="#">回到顶部</a>
</body>
</html>
4. z-index属性（防止覆盖效果）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.fathter1 {
width: 300px;
height: 300px;
background-color: red;
position: relative;
z-index: 10;
}
.son1 {
width: 100px;
height: 100px;
background-color: yellow;
position: absolute;
bottom: -10px;
right: -50px;
z-index: 3;
}
.fathter2 {
width: 300px;
height: 300px;
background-color: green;
position: relative;
z-index: 1;
}
.son2 {
width: 100px;
height: 100px;
background-color: blue;
position: absolute;
top: -20px;
right: -10px;
z-index: 4;
}
</style>
</head>
<body>
<div class="fathter1">
<div class="son1"></div>
</div>
<div class="fathter2">
<div class="son2"></div>
</div>
<form action="">
<input type="text" name="xx">
<input type="submit" value="1111">
</form>
</body>
</html>
5.js的引入方式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.box1 {
width: 200px;
height: 200px;
background-color: red;
}
</style>
</head>
<body>
<div class="box1"></div>
<script src="1.js"></script>
</body>
</html>