JSFiddle - React, Tailwind, and code Playground

HTML

<style parse-style>.css_class {color: {{angular_variable}};}</style>
<span class="css_class">{{angular_variable}} text</span><br>
<input type="text" ng-model="angular_variable">

JavaScript

var app = angular.module('app', []);

app.directive('parseStyle', function($interpolate) {
    return function(scope, elem) {
        var exp = $interpolate(elem.html()),
            watchFunc = function () { return exp(scope); };
        
        scope.$watch(watchFunc, function (html) {
            elem.html(html);
        });
    };
});

app.controller('ctrl', function($scope) {
    $scope.angular_variable = 'red';
});