Element slides under other elements on mobile
<p>First, I apologize for my horrible code. I'm working on my first site, and while it displays correctly on desktop, on mobile the float left goes underneath the rest of the site. Here's the code for some of the homepage. Any help would be greatly appreciated.</p>

<pre><code>&lt;style type="text/css"&gt;
body {
background: #90EE90; /* For browsers that do not support gradients */
background: -webkit-linear-gradient(left, #90EE90, #00FF00); /* For Safari 5.1 to 6.0 */
background: -o-linear-gradient(right, #90EE90, #00FF00); /* For Opera 11.1 to 12.0 */
background: -moz-linear-gradient(right, #90EE90, #00FF00); /* For Firefox 3.6 to 15 */
background: linear-gradient(to right, #90EE90, #00FF00); /* Standard syntax */
}
h1{font-family:Montserrat;color:000000;}
p {font-family:Montserrat;font-style:normal;font-weight:normal;color:000000;}
h2 {font-family:'Montserrat', bold;}
h3 {font-family:Montserrat;}
div.member {
    float: right;
    padding: 10px;
}
div.desc {
    float: left;
    padding:0px;
&lt;/style&gt;
&lt;body&gt;
&lt;div class="member" align="right"&gt;
&lt;h2&gt;&lt;u&gt;Social Media&lt;/u&gt;&lt;/h2&gt;
&lt;h3&gt;&lt;a href="youtube link"&gt;Youtube&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="facebook link"&gt;Facebook&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="twitter link"&gt;Twitter&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="twitch link"&gt;Twitch&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="instagram link"&gt;Instagram&lt;/a&gt;&lt;/h3&gt;
&lt;h2&gt;&lt;u&gt;Member Pages&lt;/u&gt;&lt;/h2&gt;
&lt;h3&gt;&lt;a href="name1.html"&gt;name1&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="name2.html"&gt;name2&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="name3.html"&gt;name3&lt;/a&gt;&lt;/h3&gt;
&lt;h3&gt;&lt;a href="name4.html"&gt;name4&lt;/a&gt;&lt;/h3&gt;
&lt;/div&gt;
&lt;div&gt;
&lt;h1&gt;&lt;img src="/images/logo.png" alt="Logo" hspace="20" align="left"&gt;Group name&lt;/h1&gt;
&lt;/div&gt;
&lt;div class="desc" style="height: 300px; width: 700px"&gt;
&lt;p hspace="15" align="middle"&gt;Description of site&lt;/p&gt;
&lt;/div&gt;
</code></pre>