css painted arrow

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title></title>
    <style>
        *
        {
            margin: 0px;
            padding: 0px;
        }

        #show
        {
            margin: 10px auto;
            position: absolute;
            top: 50px;
            left: 50px;
            text-align: center;
        }

        #some
        {
            width: 200px;
            margin-left: 100px;
            text-align: center;
            position: absolute;
            background-color: rgba(255, 0, 0,0.6);
            border-radius: 5px;
        }

        #info
        {
            width: 400px;
            height: 300px;
            position: absolute;
        }

        #outarrow
        {
            border-color: transparent transparent #efefef;
            border-style: solid;
            border-width: 16px;
            height: 0;
            width: 0;
            position: absolute;
            top: 0px;
            left: 184px;
        }

        #innerarrow
        {
            border-color: transparent transparent white;
            border-style: solid;
            border-width: 16px;
            height: 0;
            width: 0;
            position: absolute;
            top: 0px;
            left: 184px;
            margin-top: 6px;
        }

        #content
        {
            border: 4px solid;
            border-radius: 4px;
            border-color: #efefef;
            width: 400px;
            margin: 32px auto 0px;
            -moz-box-sizing: border-box;
            -webkit-box-sizing: border-box;
            box-sizing: border-box;
        }

            #content p
            {
                text-align: left;
                text-indent: 20px;
            }
    </style>

</head>
<body>
    <div id="show">
        <div id="some">下面就是箭头效果</div>
        <div id="info">
            <div id="outarrow"></div>
            <div id="innerarrow"></div>
            <div id="content">
                <h1> Use the arrow boundary generator </ h1> 
                <P> Point 1: box width and height are set 0, set the width of the boundary only </ p> 
                <P> 2 points: by effect of changing the border-style </ p > 
            </ div> 
        </ div> 
    </ div> 
</ body> 
</ HTML>
display effect:
Guess you like
