upstream-zulip/web/templates/modal_banner/modal_banner.hbs

<div class="main-view-banner {{banner_type}} {{classname}}">
    <div class="main-view-banner-elements-wrapper">
        {{#if banner_text}}
        <p class="banner_content">{{banner_text}}</p>
        {{else}}
        <div class="banner_content">{{> @partial-block .}}</div>
        {{/if}}
        {{#if button_text}}
        {{#if button_link}}
        <a href="{{button_link}}">
            <button class="main-view-banner-action-button{{#if hide_close_button}} right_edge{{/if}}">{{button_text}}</button>
        </a>
        {{else}}
        <button class="main-view-banner-action-button{{#if hide_close_button}} right_edge{{/if}}">{{button_text}}</button>
        {{/if}}
        {{/if}}
    </div>
    {{#unless hide_close_button}}
    <a role="button" class="zulip-icon zulip-icon-close main-view-banner-close-button" aria-label="{{t 'Dismiss' }}"></a>
    {{/unless}}
</div>