Incorrect (unnecessary classes in learning example):

// app/components/user-card.gjs
import Component from '@glimmer/component';

export class UserCard extends Component {
  <template>
    <div class="user-card">
      <div class="user-card__header">
        <h3 class="user-card__name">{{@user.name}}</h3>
        <p class="user-card__email">{{@user.email}}</p>
      </div>

      {{#if @user.avatarUrl}}
        <img class="user-card__avatar" src={{@user.avatarUrl}} alt={{@user.name}} />
      {{/if}}

      {{#if @onEdit}}
        <button class="user-card__edit-button" {{on "click" (fn @onEdit @user)}}>
          Edit
        </button>
      {{/if}}

      <div class="user-card__content">
        {{yield}}
      </div>
    </div>
  </template>
}