JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="app" ng-controller="formCtrl">
    <form name="registerForm">
        <div class="header">
            <h2>Create your account</h2>
        </div>
        <div class="form-group">
            <div class="title">First Name</div>
            <input type="text" name="firstName" ng-required class="form-control" ng-class="{empty:form.firstName.length==0}" ng-model="form.firstName" required></input>
        </div>
        <div class="form-group">
            <div class="title">Last Name</div>
            <input type="text" name="lastName" ng-required class="form-control" ng-class="{empty:form.lastName.length==0}" ng-model="form.lastName" required></input>
        </div>
        <div class="form-group">
            <div class="title">Email</div>
            <input type="email" name="email" ng-required class="form-control" ng-class="{empty:form.email.length==0}" ng-model="form.email" required></input>
        </div>
        <div class="form-group">
            <div class="title">Password</div>
            <input type="password" name="password" class="form-control" ng-class="{empty:form.password.length==0}" ng-model="form.password" required></input>
            <input type="password" name="passwordBis" class="form-control" ng-class="{empty:form.passwordBis.length==0}" ng-model="form.passwordBis" required></input>
        </div>
        <div ng-if="form.password != form.passwordBis" class="error">Passwords doesn't match.</div>
        <div class="form-group">
            <button class="btn btn-success" ng-click="register()" ng-disabled="registerForm.$invalid || form.password != form.passwordBis">Register</button><br/>
        </div>
    </form>
</div>

SCSS

form {
		min-width: 320px;
		max-width: 550px;
		margin: 50px auto 0 auto;
		.form-group {
			margin: 10px 0;
		}
		input {
			&.empty {
				border-color: red;
			}
			&[type="email"] {
				&.ng-invalid,  {
					border-color: red;
				}
			}
		}
		.error {
			color: #e4442c;
			background-color: #f2dede;
			padding-left: 5px;
		}
	}

JavaScript

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

app.controller("formCtrl", function($scope) {
    $scope.form = {
			firstName: "",
			lastName: "",
			email: "",
			password: "",
			passwordBis: ""
	};
});