Python全栈之学习CSS(2)

2024-04-02 19:04:59 704人浏览八月长安

Python 官方文档：入门教程 => 点击学习

摘要

目录1. CSS背景图1.1 背景属性1.2 背景图片引入2. 相对_绝对_固定2.1 相对定位2.2 绝对定位2.3 固定定位3. float浮动3.1 display转换元素3.

1. css背景图

1.1 背景属性

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css 背景属性</title>
    <style>
        .c1
        {
            
            width:600px;
            height:600px;
            border:solid 1px red;
            background-color: yellow;
            
            background-image:url("./images/xiao.jpg");
            
            background-repeat:no-repeat;
            
            
            
            background-attachment: fixed;
        }
        .c2
        {
            
            width:600px;
            height:600px;
            margin:10px 20px;
            border:solid 1px red;        
            
            background: url("./images/xiao.jpg") no-repeat 50% 50%;
        }
    </style>
</head>
<body>
    <div class="c1"></div>
    <div class="c2"></div>
</body>
</html>

请添加图片描述

1.2 背景图片引入

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>背景图片的引入</title>
    <style>
        
        div.c1
        {width:60px;height:60px;border:solid 1px gray;background: url("./images/tag.jpg") no-repeat;}
        div.c1:hover
        {
            background: url("./images/tag.jpg") no-repeat;
            background-position: -312px -3.5px;
        }
        .gg
        {
            width:400px;
            height:400px;
            border:solid 1px red;
        }
        
        div.c2
        {
            background: url("./images/xiao.jpg") no-repeat;
            
            
            background-size: 100% auto;
        }
        
        div.c3
        {
            background: 
                url("./images/game/map_19.gif") no-repeat 30px 80px,
                url("./images/game/map_20.gif") no-repeat 50px 50px,
                url("./images/game/map_18.gif") no-repeat 100px 50px,
                url("./images/game/map_14.gif") no-repeat 180px 100px,
                url("./images/game/map_03.gif");
        }
    </style>
</head>
<body>
    <div class="c1"></div>
    <div class="c2 gg"></div>
    <div class="c3 gg"></div>
</body>
</html>

请添加图片描述

2. 相对_绝对_固定

2.1 相对定位

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>定位:相对定位 relative</title>
    <style>
        .gg
        {
            width:200px;
            height:200px;
            border:solid 1px red;
        }
        .c1
        {background:violet;}
        .c2
        {
            background:tan;
            position:relative;
            top:10px;
            left:100px;
            z-index:2;
        }
        .c3
        {background:blue;}
        .c4
        {background:green;}
    </style>
</head>
<body>
        <!-- 
            相对定位: 参考点是他自己本身,相对于原始的位置进行定位;
            如果添加了定位:无论是添加(相对,绝对,固定)属性,添加之后会增加额外的其他属性:
            z-index 控制层叠关系: 值越大越在上层,值越小越在下层
                left
                top
                right
                bottom 
                z-index
        
        -->
        <div class="c1 gg"></div>
        <div class="c2 gg"></div>
        <div class="c3 gg"></div>
        <div class="c4 gg"></div>
</body>
</html>

2.2 绝对定位

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>定位:绝对定位 absolute</title>
    <style>
        .gg
        {width:200px;height:200px;border:solid 1px red;}
        .big
        {
            width:1000px;
            height:1000px;
            border:solid 1px red;
            margin:100px 220px;
        }
        .c1
        {
            background:violet;
            
            position: relative; 
        }
        .c2
        {
            background:tan;
            position: absolute;
            top:0px;
            left:0px;
            
            
        }
        .c3
        {background:blue;}
        .c4
        {background:green;}
    </style>
</head>
<body>
    <!-- 
        绝对定位:参考点默认参考的是body 
        效果:脱离文档流,后面的内容自动补位
        使用:绝对定位会参照父级的相对定位进行移动,如果父级中没有relative,相对于body进行定位;
            (1)把想要的父级元素变成relative
            (2)把要定位的元素变成 absolute
    -->
    <div class="big">
        <div class="c1 gg"></div>
        <div class="c2 gg"></div>
        <div class="c3 gg"></div>
        <div class="c4 gg"></div>
    </div>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>定位:绝对定位 absolute</title>
    <style>
        .gg
        {width:200px;height:200px;border:solid 1px red;}
        .big
        {
            width:1000px;
            height:1000px;
            border:solid 1px red;
            margin:100px 220px;
        }
        .c1
        {
            background:violet;
            
            position: relative; 
        }
        .c2
        {
            background:tan;
            position: absolute;
            top:0px;
            left:0px;
            
            
        }
        .c3
        {background:blue;}
        .c4
        {background:green;}
    </style>
</head>
<body>
    <!-- 
        绝对定位:参考点默认参考的是body 
        效果:脱离文档流,后面的内容自动补位
        使用:绝对定位会参照父级的相对定位进行移动,如果父级中没有relative,相对于body进行定位;
            (1)把想要的父级元素变成relative
            (2)把要定位的元素变成 absolute
    -->
    <div class="big">
        <div class="c1 gg"></div>
        <div class="c2 gg"></div>
        <div class="c3 gg"></div>
        <div class="c4 gg"></div>
    </div>
</body>
</html>

2.3 固定定位

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>定位:固定定位 fixed</title>
    <style>
        
        *
        {margin:0px;padding:0px;}
        body
        {height:2000px;}
        .c1
        {
            width:500px;
            height: 600px;
            border:solid 1px red;
            background-color: green;
            position: fixed;
            left:50%;
            margin-left:-250px;
            top:50%;
            margin-top:-300px;
        }
        
        img
        {
            position:fixed;
            bottom:20px;
            left:-100px; 
            transition: all 1s ease 0.1s;           
        }
        
        img:hover
        {
            left:0px;
            background-color: red;
        }

    </style>
</head>
<body>
     <img src="images/xiao.jpg"/>
     <div class="c1">我没动</div>
     <p>1111222333444</p>
</body>
</html>

3. float浮动

3.1 display转换元素

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>display 转换元素</title>
    <style>
        div
        
        {display:inline;border:solid 1px red;width:1000px;height:20px;}
        span
        
        {display:block;width:100px;height:50px;border:solid 1px red;}
        a
        
        {display:inline-block;width:500px;height:30px;border:solid 1px red;}        
        p
        
        {display:none;}
    </style>
</head>
<body>
    <!-- 元素的分类:
        块状元素 : block
        行内元素 : inline
        行内块状元素  : inline-block
    -->
    <div>第一个div</div>
    <div>第二个div</div>
    <span>我是span1</span>
    <span>我是span2</span>
    <a href="#">我是链接1</a>
    <a href="#">我是链接2</a>
    <p>12345</p>
</body>
</html>

3.2 float浮动

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>float 浮动</title>
    <style>
        .content
        {width:700px;clear:both;}
        .content .c1
        {background: red;width:100px;height:100px;float:left;}
        .content .c2
        {background: tan;width:100px;height:100px;float:left;}
        .content .c3
        {background:blue;width:100px;height:100px;float:left;}
        .content .c4
        {background:green;width:100px;height:100px;float:left;}
        .content2
        {width:700px;height:500px;border:solid 1px red;clear:both;}
        #a1
        {float:left;width:100px;height:100px;border:solid 1px red;}
        #a2
        {display:block;width:100px;height:100px;border:solid 1px red;background: teal;clear: both;}
    </style>
</head>
<body>
    <!-- 
    # ###块状元素浮动:
    float:left  向左浮动  ,元素脱离原始文档流,后面的内容自动补齐;
    float:right 向右浮动  ,元素脱离原始文档流,后面的内容自动补齐;
    目的: 让块状元素在一排显示 
    clear:both; 清除两边的浮动
    -->
    <div class="content">
        <div class="c1"></div>
        <div class="c2"></div>
        <div class="c3"></div>
        <div class="c4"></div>
    </div>
    <!-- 
    # ###行内元素浮动:
        如果对行内元素进行浮动:
        默认会把行内元素升级成行内块状元素,可以设置宽和高 
        消除浮动产生的影响:clear:both;
    -->
    <div class="content2">
        <a href="#" id="a1">点击我跳转1</a>
        <a href="#" id="a2">点击我跳转2</a>
    </div>
</body>
</html>

4. html里面的bug

4.1 float内容塌陷问题

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>float 浮动</title>
    <style>
        .content
        {width:700px;clear:both;}
        .content .c1
        {background: red;width:100px;height:100px;float:left;}
        .content .c2
        {background: tan;width:100px;height:100px;float:left;}
        .content .c3
        {background:blue;width:100px;height:100px;float:left;}
        .content .c4
        {background:green;width:100px;height:100px;float:left;}
        .content2
        {width:700px;height:500px;border:solid 1px red;clear:both;}
        #a1
        {float:left;width:100px;height:100px;border:solid 1px red;}
        #a2
        {display:block;width:100px;height:100px;border:solid 1px red;background: teal;clear: both;}
    </style>
</head>
<body>
    <!-- 
    # ###块状元素浮动:
    float:left  向左浮动  ,元素脱离原始文档流,后面的内容自动补齐;
    float:right 向右浮动  ,元素脱离原始文档流,后面的内容自动补齐;
    目的: 让块状元素在一排显示 
    clear:both; 清除两边的浮动
    -->
    <div class="content">
        <div class="c1"></div>
        <div class="c2"></div>
        <div class="c3"></div>
        <div class="c4"></div>
    </div>
    <!-- 
    # ###行内元素浮动:
        如果对行内元素进行浮动:
        默认会把行内元素升级成行内块状元素,可以设置宽和高 
        消除浮动产生的影响:clear:both;
    -->
    <div class="content2">
        <a href="#" id="a1">点击我跳转1</a>
        <a href="#" id="a2">点击我跳转2</a>
    </div>
</body>
</html>

4.2 margin-top失效问题

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>margin-top失效问题</title>
    <style>
        *
        {margin:0px;padding:0px;}
        .box1
        {width:100px;height:100px;margin-top:10px;border:solid 1px red;}
        .father
        {width:300px;height:300px;background: yellow;overflow: hidden;}
        .son
        {width:150px;height:150px;margin-top:50px;}
    </style>
</head>
<body>
    <!-- overflow: hidden; overflow auto 如果内容超出边框，会以下拉框的形式显示，不会溢出 -->
    <div class="box1">
        sdfsf
    </div>
    <div class="father">
        <div class="son">12</div>        
    </div>
</body>
</html>

4.3 overflow

<!DOCTYPE html>
<html>
    <head>
    <meta charset="utf-8" />
    <style>
        .test {
            overflow: hidden;
            width: 200px;
            height: 100px;
            background: #eee;
        }
    </style>
    </head>
    <body>
        <!-- overflow:hidden 对超出部分内容进行隐藏 -->
        <div class="test">
            <p>苏打速度</p>
            <p>苏打速度</p>
            <p>苏打速度</p>
            <p>苏打速度</p>
            <p>苏打速度</p>
        </div>
    </body>
</html>