chromium/chrome/browser/resources/ash/settings/os_about_page/edit_hostname_dialog.html

<style include="settings-shared">
  :host {
    --cr-dialog-width: 335px;
    --cr-dialog-title-slot-padding-start: 24px;
    --cr-dialog-title-slot-padding-end: 24px;
    --cr-dialog-title-slot-padding-top: 24px;
    --cr-dialog-title-slot-padding-bottom: 0;
    --cr-dialog-body-padding-horizontal: 24px;
    --cr-dialog-button-container-padding-horizontal: 24px;
    --cr-dialog-button-container-padding-bottom: 20px;
  }

  :host([is-input-invalid_]) #inputInfo {
    color: var(--cros-text-color-alert);
  }

  #inputContainer {
    position: relative;
  }

  #deviceNameInfo {
    margin-bottom: 24px;
  }

  #deviceName {
    margin: 8px 0 24px 0;
  }

  #inputInfo {
    background-color: var(--cros-bg-color-elevation-3);
    color: var(--cros-text-color-secondary);
    font-size: var(--cr-form-field-label-font-size);
    font-weight: 400;
    height: 30px;
    line-height: var(--cr-form-field-label-line-height);
    padding-top: 8px;
    position: absolute;
    top: 97px;
    width: 100%;
  }

  #inputCount {
    position: absolute;
    right: 0;
    top: 8px;
  }

  :host-context([dir='rtl']) #inputCount {
    left: 0;
    right: auto;
  }

  #inputSubtitle {
    display: block;
    width: 290px;
  }
</style>
<cr-dialog id="dialog" show-on-attach>
  <div slot="title">$i18n{aboutEditDeviceName}</div>
  <div slot="body">
    <div id="inputContainer">
      <div id="deviceNameInfo">$i18n{aboutDeviceNameInfo}</div>
      <!-- Set error-message so then it is read out by ChromeVox
          when cr-input is invalid. Since we already display the error
          message in #inputInfo, this is visually hidden by #inputInfo. -->
      <cr-input id="deviceName"
          value="{{deviceName_}}"
          spellcheck="false"
          invalid="[[isInputInvalid_]]"
          aria-label="[[i18n('aboutDeviceNameInputA11yLabel')]]"
          aria-description=
              "[[i18n('aboutDeviceNameConstraintsA11yDescription')]]"
          error-message="[[i18n('aboutDeviceNameConstraintsA11yDescription')]]"
          autofocus>
      </cr-input>
      <!-- Visual error message is different from the one read out by
          ChromeVox, hence the need for this #inputInfo div. -->
      <div id="inputInfo" aria-hidden="true">
        <span id="inputSubtitle">$i18n{aboutDeviceNameConstraints}</span>
        <span id="inputCount">[[inputCountString_]]</span>
      </div>
    </div>
  </div>
  <div slot="button-container">
    <cr-button id="cancel" class="cancel-button"
        on-click="onCancelClick_">
      $i18n{cancel}
    </cr-button>
    <cr-button id="done" class="action-button"
        on-click="onDoneClick_"
        disabled="[[isInputInvalid_]]"
        aria-label="[[i18n('aboutDeviceNameDoneBtnA11yLabel', deviceName_)]]">
      $i18n{done}
    </cr-button>
  </div>
</cr-dialog>