JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div id="wrap">
        <div id="left">Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left Left</div>
        <div id="right">Right Right Right Right</div>
    </div>
</body>

CSS

#wrap {
    display:flex;
    justify-content:space-between;
}

#left {
    background:red;
    overflow:hidden;
    text-overflow:ellipsis;
    white-space:nowrap;
    flex:1;
}

#right {
    background:orange;
}