JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <nav class="nav">
        <h1 class="navh"> Menu</h1>
        <ul>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
        </ul>
        <h1 class="navh"> Menu</h1>
        <ul>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
            <li>
                <a href="#">Menu</a>
            </li>
        </ul>
        <div class="downnav">
            <p>Stopka</p>
        </div>
    </nav>

<div class="container">
    <article>Lorem ipsum dolor sit amet consectetur adipisicing elit. Voluptatibus dignissimos consectetur quod esse vel libero nesciunt
        consequuntur accusantium voluptas repellendus? Dolor dolorem quaerat cupiditate, nulla molestias veniam facere nam
        perspiciatis.</article>
    </div>

CSS

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: #1c2238;
}

.nav {
    font-family: 'Lato', sans-serif;
    display: flex;
    background-color: #252c48;
    align-content: flex-start;
    width: 17%;
    height: 100vh;
    flex-direction: column;
    align-items: center;
    border-right: 1px solid rgb(63, 63, 63);
}

.navh {
    padding-top: 5px;
    margin-left: 15px;
    color: #d4d3e5;
}

nav ul {
    padding: 20px;
    display: block;
}

.nav li {
    list-style: none;
    margin-left: 20px;
    list-style: none;
    padding: 15px;
}

.nav a {
    text-decoration: none;
    color: #525975;
    font-weight: bold;
}

.nav a:hover {
    color: #d5d4e6;
    transition: all 0.5s ease-in-out;
}

.downnav {
    position: absolute;
    bottom: 0px;
}

.downnav p {
    color: #525975;
    padding-bottom: 15px;
    font-weight: bold;
    font-size: 10px;
}

.container {
   
}