body {
    margin: 0;
    font-family: Arial, sans-serif;
  }
  .navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: #fff;
    display: flex;
    align-items: center;
    padding: 10px 20px;
    border-bottom: 1px solid #ccc;
    z-index: 1000;
  }
  .navbar .logo {
    font-weight: bold;
    font-size: 20px;
    margin: 22px;
  }
  .navbar input {
    width: 40%;
    padding: 6px;
  }

  /* Caixa fixa no rodapé */
  .footer-fixed {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: #222;
    color: #fff;
    text-align: center;
    padding: 10px;
    font-size: 14px;
    z-index: 1000;
  }

  /* Layout de duas colunas com anúncio fixo */
  .container {
    display: flex;
    margin-top: 30px; /* espaço por causa da navbar */
    padding-bottom: 60px; /* espaço para o rodapé fixo */
  }

  .col-esquerda {
    width: 20%;
    padding: 20px;
    background: #f0f0f0;
  }

  .anuncio-fixo {
    position: sticky;
    top: 90px;
    background: black;
    padding: 10px;
    border: 1px solid #999;
  }

  .col-direita {
    width: 80%;
    padding: 20px;
    margin: 20px;
  }

  /* Testes de position: static, relative, absolute */
  .static-box {
    position: static;
    background: #d6eaff;
    padding: 15px;
    margin-top: 20px;
  }

  .relative-box {
    position: relative;
    background: #ffd6d6;
    padding: 15px;
    top: 20px;
    left: 10px;
  }

  .absolute-parent {
    position: relative;
    background: #e8ffd6;
    margin-top: 30px;
    padding: 20px;
    height: 200px;
  }
  .absolute-child {
    position: absolute;
    top: 20px;
    right: 20px;
    background: #cce0ff;
    padding: 30px;