JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header">
        <div class="logo">
            .logo
        </div>
        <div class="nav-main">
            .nav-main
        </div>
        <div class="nav-sub">
            .nav-sub
        </div>
    </div>

CSS

.logo {
            float: left;
            width: 260px;
            height: 50px;
            background: green;
        }

        .nav-main {
            background: red;
        }

        .nav-sub {
            background: blue;
        }
.header{
 min-width:320px;   
}