Angularjs 无法为输入元素绑定自动聚焦属性

当我上传登录页面时，当我点击屏幕时，按钮将变为灰色。按钮将变为蓝色焦点缺失。请帮助我解决此问题

Html代码：

<main id="frontpage">
    <form id="login-form" name="login_form" novalidate>

        <div ng-class='{"input-block": true, "input-block-focus": username_focused, "input-error": login_form.username.$touched&&login_form.username.$invalid, "input-block-disabled":submit_button_value}'>
            <div>
                <label class="labels">Username</label>
            </div>
            <input class="loginForm_input" name="username" ng-model="user.username" ng-focus="username_focused=true" ng-blur="username_focused=false"
                placeholder="Enter your username" type="text" ng-disabled="submit_button_value" required>

        </div>
        <div ng-class='{"input-block": true, "input-block-focus": password_focused, "input-error": login_form.password.$touched&&login_form.password.$invalid, "input-block-disabled":submit_button_value}'>

            <div>
                <label class="labels">Password</label>
            </div>
            <input class="loginForm_input" name="password" ng-model="user.password" ng-focus="password_focused=true" ng-blur="password_focused=false"
                placeholder="Enter your password" type="{{password_type}}" ng-disabled="submit_button_value" required>
            <span ng-click="showHidePassword()" ng-class='{"eye-icon-open":password_visible, "eye-icon-close":!password_visible, "pull-right": true}'></span>
        </div>
        <div>

            <button ng-class='["btn", "btn-primary", "horizontal-center", "submit-button",{"submit-button-loading": !submit_button_value }]'
                ng-disabled="login_form.$invalid || submit_button_value" ng-click="signin()">

                <span ng-if="!submit_button_value">Login</span>
                <span ng-if="submit_button_value" class="fa fa-spinner fa-spin"></span>
            </button>
        </div>
    </form>
</main>

用户名
密码
登录

由于“btn”、“btn主”、“水平中心”、“提交按钮”等类比较常见，请尝试以下操作：

<button class="btn btn-primary horizontal-center submit-button" ng-class="{'submit-button-loading': !submit_button_value }"
                ng-disabled="login_form.$invalid || submit_button_value" ng-click="signin()">

我不明白为什么ng类中的所有这些类-你能试着只保留“输入块”和“输入错误”吗？只使用自动对焦，就像类“submit buton”或“submit button loading”覆盖颜色一样？cz引导类“btn primary”应该为您提供蓝色。