class MainWindow extends HTMLElement {
  static observedAttributes = ['title', 'description'];

  constructor() {
    super();
    this.attachShadow({ mode: 'open' });
  }
  
  connectedCallback() {
    this.render();
  }

  attributeChangedCallback() {
    this.render();
  }

  render() {
    const title = this.getAttribute('title') || "No title";
    const description = this.getAttribute('description') || "No description";

    this.shadowRoot.innerHTML = `
    <style>
      #window {
        width: 900px;
        height: 577px;
        background: #FFFFFF 0% 0% no-repeat padding-box;
        box-shadow: 0px 5px 12px #0000001F;
        border-radius: 20px;
        opacity: 1;
      }
      #content {
        width: 800px;
        margin: 0 50px 13px 50px;
      }
      h1 {
        top: 221px;
        margin: 50px 50px 13px 50px;
        height: 49px;
        text-align: center;
        font-size: 40px;
        font-family: "Montserrat", sans-serif;
        font-weight: normal;
        letter-spacing: 0px;
        color: #333333;
        opacity: 1;
      }
      p {
        margin: 0 50px 0 50px;
        text-align: center;
        height: 74px;

        /* UI Properties */

        text-align: center;
        font-size: 18px;
        font-family: "Montserrat", sans-serif;
        font-weight: normal;
        letter-spacing: 0px;
        color: #333333;
        opacity: 1;
      }
    </style>
    <div id="window">
      <h1>${title}</h1>
      <p>${description}</p>
      <div id="content" >
        <slot></slot>
      <div/>
    </div>
    `;
  }
}

customElements.define('main-window', MainWindow);