Markdown在线编辑器

<script src="https://cdn.bootcss.com/showdown/1.3.0/showdown.min.js"></script>

<div class="editor-box">
    <p class="head-name">Markdown编辑器</p>
    <textarea class="markdown-editor" id="editor" onkeyup="preview()">### Hello Markdown Edit!</textarea>
</div>  
<div class="preview-box">
    <p class="head-name">预览</p>
    <div class="markdown-preview" id="preview">

    </div>
</div>

body{margin: 0;background-color: #000;}
//预览基础样式
blockquote {
    border-left:#eee solid 5px;
    padding-left:20px;
}
ul li {
    line-height: 20px;
}
p{line-height: 30px;font-size: 18px;}
pre{overflow-x: auto;font-family: '微软雅黑','Rotis','sans-serif';background: #000;width: 100%;border: 1px solid #000;border-radius: 5px;box-sizing: border-box;padding: 10px;}
code {
    color:#fff;
    width: 100%;
    font-size: 16px;
}  
//盒子样式 
.editor-box{
    width:50%;
    background-color:#fff;
    float:left;
    box-sizing:border-box;
    border-right:1px solid #ccc;
}
.preview-box{
    width:50%;
    background-color:#fff;
    float:right;
}
.head-name{
    height:50px;
    line-height:50px;
    text-align:center;
}
.markdown-editor,.markdown-preview{
    width:100%;
    box-sizing:border-box;
    resize:none;
    height:500px;
    padding:10px;
    text-align:left;
    color:#444;
    border:1px solid #aaa;
    display:block;
    overflow:auto;
}

(function(win,doc){
    var converter = new showdown.Converter();
    function $(elem){
        return doc.getElementById(elem);
    }
    var preview = win.preview = function(){
        $('preview').innerHTML = converter.makeHtml($('editor').value);
    }
    preview();
})(window,document)