盒子模型和边框设置

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>Document</title>
    <style type="text/css">
        *{
            padding:0;
            margin:0;
        }
        .box{
            width:300px;
            height:200px;
            padding:50px;
            border:10px solid red;
            margin:20px;
        }
        .box2{
            width: 300px;
            height: 200px;
            padding:30px;
            border:30px solid #eee;
            margin:20px;
        }
        .box3{
            width: 300px;
            height: 300px;
            padding:50px;
            border:20px solid lightblue;
            margin:40px;
            background-color: yellowgreen;
            /*background-image: url(images/watermelon.jpg);*/
            background-image: url(images/star.gif);
        }

    </style>
</head>
<body>
    <div class="box">盒子</div>
    <div class="box2">2号盒子</div>
    <div class="box3">3号</div>

</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>Document</title>
    <style type="text/css">
        *{
            padding:0;
            margin:0;
        }
        
        .box{
            width:0px;
            height:0;
            border:60px solid #fff;
            border-top-color:red;
            border-bottom:none;
            /*border-right-color:green;
            border-bottom-color:orange;*/
            margin:50px;
        }
        .box2{
            width:0px;
            height:0px;
            border-top:60px solid red;
            border-right :60px solid transparent;
            border-bottom :60px solid transparent;
            border-left :60px solid transparent;
            /*border-right-color:green;
            border-bottom-color:orange;*/
            margin:50px;
        }

    </style>
</head>
<body>
    <div class="box"></div>
    <div class="box2"></div>

</body>
</html>

下面两个距离不一样，就算因为一个 float:left;

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>Document</title>
    <style type="text/css">
        /*清除默认样式*/
        *{
            padding:0;
            margin:0;
        }
        ul,ol{
            list-style: none;
        }
        a{
            text-decoration: none;
            color:#333;
        }
        .box1{
            width: 200px;
            height: 200px;
            background-color: lightblue;
            
        }
        .box1{
            margin-bottom: 130px;
        }
        .box2{
            margin-top: 80px;
            float:left;
            
        }


    </style>
</head>
<body>
    <div class="box1">1</div>
    <div class="box1 box2 ">2</div>

    

</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>Document</title>
    <style type="text/css">
        /*清除默认样式*/
        *{
            padding:0;
            margin:0;
        }
        ul,ol{
            list-style: none;
        }
        a{
            text-decoration: none;
            color:#333;
        }
        .box1{
            width: 200px;
            height: 200px;
            background-color: lightblue;
            
        }
        .box1{
            margin-bottom: 130px;
        }
        .box2{
            margin-top: 80px;

            
        }


    </style>
</head>
<body>
    <div class="box1">1</div>
    <div class="box1 box2 ">2</div>

    

</body>
</html>