JSFiddle - React, Tailwind, and code Playground

HTML

<div class="body">
<div class="container">
    <div class="contacts-container">
    <div class="contacts">Contacts
    </div>
    </div>
</div>
<div class="menu-container">
    <div class="container right">
    <div class="menu">Menu
    </div>
    </div>
</div>
</div>

CSS

.body {
    width: 100%;
    overflow: hidden;
}
.container {
    width: 600px;
    margin: 0 auto;
    border: 1px solid red;
}
.contacts-container {
    width: 2000px;
    margin-top: 100px;
    background: rgba(0,0,255,.5);
    color: #fff;
}
.contacts {
    background: green;
    padding: 10px;
    width: 300px;
    margin-left: 280px;
}
.menu-container {
    background: yellow;
}
.menu {
    width: 400px;
    padding: 10px;
    background: blue;
    color: #fff;
}
.right {
    display: flex;
    justify-content: flex-end;;
}