}
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/mvc/4.0/jquery.validate.unobtrusive.min.js"></script>
<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>

<!------ Include the above in your HEAD tag ---------->
<link href="/Content/Loginstyle.css" rel="stylesheet" />

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.3.1/css/all.css" integrity="sha384-mzrmE5qonljUremFsqc01SB46JvROS7bZs3IO2EmfFsd15uHvIt+Y8vEf7N7fWAU" crossorigin="anonymous">

<div class="container">
    <div class="d-flex justify-content-center h-100">
        <div class="card">
            <div class="card-header">
                <div class="d-flex justify-content-end social_icon">
                </div>
            </div>
            <div class="card-body">
<form action="/Account/CheckUser" method="post"><input name="__RequestVerificationToken" type="hidden" value="N7M4o9Lm_PiGDYgsHi6JMqh8MGRpjV012dJfLZhiuWnAnEf6f4czSPKB0s4BCXoFkLQUa3QUiD0kyBKj4oGbg4cN2h0cGiKyH1zat7Uh5WQ1" />                    <div class="input-group form-group">
                        <div class="input-group-prepend">
                            <span class="input-group-text"><i class="fas fa-user"></i></span>
                        </div>
                        
                        <input class="form-control" data-val="true" data-val-length="The U_Name  must be at least 1 characters long." data-val-length-max="150" data-val-length-min="1" data-val-required="The U_Name  field is required." id="U_Name" name="U_Name" type="text" value="" />
                    </div>
                    <div style="color:blue">
                        <span class="field-validation-valid" data-valmsg-for="U_Name" data-valmsg-replace="true"></span>
                    </div>
                    <div class="input-group form-group">
                        <div class="input-group-prepend">
                            <span class="input-group-text"><i class="fas fa-key"></i></span>
                        </div>
                        
                        <input class="form-control" data-val="true" data-val-length="The U_Password  must be at least 1 characters long." data-val-length-max="150" data-val-length-min="1" data-val-required="The U_Password  field is required." id="U_Password" name="U_Password" type="password" />

                    </div>
                    <div style="color:blue">
                        <span class="field-validation-valid" data-valmsg-for="U_Password" data-valmsg-replace="true"></span>
                    </div>
                    <div class="row align-items-center remember">
                        <input type="checkbox">Remember Me
                    </div>
                    <div class="form-group">
                        <input type="submit" value="Login" class="btn float-right login_btn">
                    </div>
</form>            </div>
            <div class="card-footer">
                <div class="d-flex justify-content-center links">
                    Don't have an account?<a href="#">Sign Up</a>
                </div>
                <div class="d-flex justify-content-center">
                    <a href="#">Forgot your password?</a>
                </div>
            </div>
        </div>
    </div>
</div>