chromium/ash/webui/common/resources/cellular_setup/provisioning_page.html

<style include="iron-flex cr-hidden-style">
  paper-spinner-lite {
    height: 32px;
    width: 32px;
  }

  #portalContainer {
    height: 100%;
    width: 100%;
  }

  #errorIllustration,
  #errorIllustrationJelly {
    height: 100%;
    width: 100%;
  }

  #errorIllustration {
    background-image: url(chrome://resources/ash/common/cellular_setup/error.svg);
    background-position: center center;
    background-repeat: no-repeat;
    background-size: contain;
  }

  @media(prefers-color-scheme: dark) {
    #errorIllustration {
      background-image: url(chrome://resources/ash/common/cellular_setup/error_dark.svg);
    }
  }

  :host-context(body.jelly-enabled) #errorIllustration {
    display: none;
  }

  :host-context(body:not(.jelly-enabled)) #errorIllustrationJelly {
    display: none;
  }
</style>
<base-page title="[[getPageTitle_(
                        showError, carrierName_, hasCarrierPortalLoaded_)]]"
    message="[[getPageMessage_(showError)]]">
  <div slot="page-body" class="layout horizontal center-center">
    <paper-spinner-lite active
        hidden$="[[!shouldShowSpinner_(
                        showError, hasCarrierPortalLoaded_)]]">
    </paper-spinner-lite>
    <div id="portalContainer"
        hidden$="[[!shouldShowPortal_(
                        showError, hasCarrierPortalLoaded_)]]">
    </div>
    <div id="errorIllustration" hidden$="[[!showError]]"></div>
    <iron-icon id="errorIllustrationJelly" icon="cellular-setup-illo:error"
        hidden$="[[!showError]]">
    </iron-icon>
  </div>
</base-page>