JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header">
     <div class="logo">
        <h1 id="logo-large">FAT</h1> <h1 id="logo-small">HEAD</h1>
        <nav>
        <ul>
            <li><a href="index.html">Home</a></li>
            <li><a href="#">About</a></li>
            <li><a href="#">Contact</a></li>
            <li><a href="#">Categories</a></li>
        </ul>
        </nav>
    </div>
</div>
<div class="main-content">
    <h1>Welcome to my blog!</h1>
    <p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p> <p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p> <p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p> <p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p> <p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p> <p>This would be where all the content inside the blog post goes.</p><p>This would be where all the content inside the blog post goes.</p><p>This would be where all the...

CSS

.header{
    position: fixed;
    left:0;
    right:0;
    top:0;
}
html body {
 padding-top: 65px;
}
/***********************************
          LOGO
***********************************/
.header{
background-color: skyblue;
margin:0;
padding:0;
width: 100%;
}
.logo{
text-align: left;
display: block;
margin:0 15px 0px 15px;
}
#logo-large{
display: inline;
font-size: 3em;
font-weight: 200%;
font-family: 'Dosis' , sans-serif;
}
#logo-small{
display: inline;
font-weight:0;
font-size: 2.5em;
font-family: 'Dosis' ,sans-serif;
}
/************************************
           NAVIGATION
************************************/
nav ul{
list-style-type:none;
/****display: block;
padding: 5px;
margin: 5px;
text-align: center;****/
}
nav{
display:inline;
float: right;
}
nav ul li{
display: inline-block;
padding: 5px 0px;
margin: 0;
}
nav ul li a{
text-decoration: none;
padding:20px 12px 12px 12px;
color:black;
font-family: 'Muli', sans-serif;
font-size: 1.25em;
}
nav ul li a:active, nav ul li a:hover{
background-color: deepskyblue;
color: white;
}
/*************************************
           main content
*************************************/
.main-content{
background-color: grey;
font-family: 'Muli', sans-serif;
margin:0;
padding:10px;
border: 1px solid black;
}
body{
margin:0;
padding:0;
}