JSFiddle - React, Tailwind, and code Playground

HTML

<div data-ng-app>
    <div data-ng-controller="ProgressBarController">
        <div class="progress-bar-container">
            <div class="progress-bar" ng-style="{'width' : '{{ progress }}'% }">{{ progress }}</div>
        </div>
    </div>
</div>

CSS

.progress-bar-container {
    width: 300px;
    height: 100px;
    box-sizing: border-box;
    border: 1px solid black;
}
.progress-bar {
    height: 100px;
    background-color: green;
}

JavaScript

function ProgressBarController($scope) {
    $scope.progress = 20;
}