两种方法，一种是右边放个详情页的区域，通过点击回复，把隐藏的详情页显示出来，
一种是右边放个iframe，点击时修改它的src，在iframe窗口里跳转页面
先给你贴出来第一种方法，等下发第二种， 如有帮助，麻烦点下 【采纳此答案】
<!doctype html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
<title>在线问答系统-首页</title>
<!-- Bootstrap -->
<link rel="stylesheet" href="./assets/plugins/bootstrap/css/bootstrap.min.css" rel="stylesheet">
<!-- HTML5 shim 和 Respond.js 是为了让 IE8 支持 HTML5 元素和媒体查询（media queries）功能 -->
<!-- 警告：通过 file:// 协议（就是直接将 html 页面拖拽到浏览器中）访问页面时 Respond.js 不起作用 -->
<!--[if lt IE 9]>
<script src="./assets/plugins/html5shiv.min.js"></script>
<script src="./assets/plugins/respond.min.js"></script>
<![endif]-->
<link rel="stylesheet" href="./assets/style/common.css">
<link rel="stylesheet" href="./assets/style/index.css">
<style type="text/css">
.right-menu-box2{
display: flex;
}
#content{
width: 30%;
}
#detail{
width: 70%;
min-height: 400px;
display: flex;
justify-content: center;
align-items: center;
visibility: hidden;
}
</style>
</head>
<body class="layout" id="top">
<!-- 顶部导航 -->
<div class="layout-header">
<nav class="navbar navbar-default navbar-fixed-top">
<div class="container">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">医疗知识—在线问答系统</a>
</div>
</div>
</nav>
</div>
<!-- 顶部导航 -->
<div class="layout-main">
<div class="container">
<div class="row">
<!-- flash消息 -->
<!-- 轮播图 -->
<div id="id-index-banner" class="carousel slide" data-ride="carousel">
<!-- Wrapper for slides -->
<div class="carousel-inner" role="listbox">
<div class="item active">
<img src="./assets/home/banner/banner1.png" alt="首页轮播图">
</div>
<div class="item">
<img src="./assets/home/banner/banner2.png" alt="首页轮播图">
</div>
<div class="item">
<img src="./assets/home/banner/banner3.png" alt="首页轮播图">
</div>
</div>
<!-- Controls -->
<a class="left carousel-control" href="#id-index-banner" role="button" data-slide="prev">
<span class="glyphicon glyphicon-chevron-left" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="right carousel-control" href="#id-index-banner" role="button" data-slide="next">
<span class="glyphicon glyphicon-chevron-right" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div>
<!-- //轮播图 -->
<!-- 右侧菜单 -->
</div>
<div class="right-menu-box2">
<div id="content">
<div class="info_box">
<div class="info_r">
<img src="./assets/home/qa/touxiang1.png" class='pic_r'>
<span class='infor'>医生，在吗？</span>
</div>
<div class="info_l">
<img src="./assets/home/qa/touxiang2.png" class='pic_l'>
<span class='infoo'>您好，请问有什么问题？</span>
</div>
</div>
<form action="">
<img src="./assets/home/qa/touxiang1.png" id='pic'>
<input type="text" placeholder='欢迎咨询!' id='inp'>
<input type="button" value='发送' id='send'>
</form>
</div>
<div id="detail">
详情页
</div>
</div>
</div>
<script>
var send =document.getElementById('send');
var img =document.getElementById('img');
var txt =document.getElementById('inp');
var info_box = document.getElementsByClassName('info_box')[0];
var onoff=true;
pic.onclick=function(){
if(onoff){
img.src='./assets/home/qa/touxiang1.png';
onoff=false;
}
else{
img.src='/assets/home/qa/touxiang3.png';
onoff=true;
}
};
// 给发送按钮添加点击事件l
send.onclick=function(){
if(txt.value===''){
alert('请输入内容');
}
else{
var nDiv = document.createElement('div');
var spans = document.createElement('span');
var imgs = document.createElement('img');
var sTxt = document.createTextNode(txt.value);
var info_box = document.getElementsByClassName('info_box')[0];
spans.appendChild(sTxt);
nDiv.appendChild(spans);
nDiv.appendChild(imgs);
// nDiv.style.display='block';
info_box.insertBefore(nDiv,info_box.lastChild);
spans.className='infor';
nDiv.className='info_r';
imgs.src='./assets/home/qa/touxiang1.png';
var nDiv = document.createElement('div');
var spans = document.createElement('span');
var imgs = document.createElement('img');
var sTxt = document.createTextNode("你说啥？");
var info_box = document.getElementsByClassName('info_box')[0];
// var a = document.createElement('a');
// a.href = './follow.html' ;
// a.appendChild(sTxt);
spans.appendChild(sTxt);
var detail = document.getElementById('detail')
spans.onclick = function(){
detail.style.visibility = 'initial'
}
// spans.appendChild(sTxt);
nDiv.appendChild(spans);
nDiv.appendChild(imgs);
// nDiv.style.display='block';
info_box.insertBefore(nDiv,info_box.lastChild);
spans.className='infol';
nDiv.className='info_l';
imgs.src='./assets/home/qa/touxiang2.png';
/*
if(onoff==true){
spans.className='infor';
nDiv.className='info_r';
imgs.src='img/2.png';
}
if(onoff==false){
spans.className='infol';
nDiv.className='info_l';
imgs.src='img/1.png';
}
*/
}
txt.value='';
}
</script>
<!-- //右侧快捷菜单区域 -->
</div>
</div>
<!-- 页面右下角的菜单（返回顶部） -->
<div class="layout-footer">
<audio src="./assets/ge.mp3" controls autoplay loop></audio>
</div>
<!-- 页面右下角的菜单（返回顶部） -->
<!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
<script src="./assets/plugins/jquery-3.4.1.js"></script>
<!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
<script src="./assets/plugins/bootstrap/js/bootstrap.min.js"></script>
</body>
</html>
