test1/public/basic/views/site/login.php

<?php

/* @var $this yii\web\View */
/* @var $form yii\bootstrap\ActiveForm */
/* @var $model app\models\LoginForm */

use yii\helpers\Html;
use yii\bootstrap\ActiveForm;

$this->title = 'Login';
//$this->params['breadcrumbs'][] = $this->title;
?>
<style>

    body, html {
        height: 100%;
        background-repeat: no-repeat;
        background-image: linear-gradient(rgb(255, 255, 255), rgb(28, 159, 128));
    }

    .card {
        max-width: 420px;
        padding: 40px 40px;
        margin-right:auto;
        margin-left: auto;
        margin-top: 200px;
    }
</style>
<div class="card">
    <div class="col-lg-12"><h1>Login</h1></div>
    <?php $form = ActiveForm::begin([
        'id' => 'login-form', 'fieldConfig' => [
            'template' => "<div class=\"col-lg-12\">{label}</div><div class=\"col-lg-12\">{input}</div>\n<div class=\"col-lg-12\">{error}</div>",
        ],
    ]); ?>

        <?= $form->field($model, 'username')->textInput(['autofocus' => true]) ?>

        <?= $form->field($model, 'password')->passwordInput() ?>

        <!--<?= $form->field($model, 'rememberMe')->checkbox([
            'template' => "<div class=\"col-lg-offset-1 col-lg-3\">{input} {label}</div>\n<div class=\"col-lg-8\">{error}</div>",
        ])
        ?>-->

        <div class="form-group">
            <!--<div class="col-lg-offset-1 col-lg-11">-->
                <?= Html::submitButton('Login', ['class' => 'btn btn-primary center-block', 'name' => 'login-button']) ?>
            <!--</div>-->
        </div>

    <?php ActiveForm::end(); ?>
</div>