JSFiddle - React, Tailwind, and code Playground

HTML

<div class="nav">
  <div class="item">home</div>
  <div class="item">login</div>
  <div class="item">signup</div>
</div>

CSS

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;    
    height: 100%;
}

.nav {
    display: table; // To center without giving a fixed width.
    margin: 0 auto;
    margin-top: 30px;
}
.nav:before, .nav:after {
    display: table;
    content: '';
}
.nav:after {
    clear: both;
}
.nav .item {
    float: left;
    padding: 8px;
    background: #f5f5f5;
}
.nav .item:hover {
    background: #e5e5e5;
    cursor: pointer;
}
.nav .item.active {
    background: #e5e5e5;
}