:root {
    --bg-color: #fff;
    --text-color: #222;
    --link-color: #9a0707;
    --header-bg: #f9f0f0;
    --border-color: #9a0707;
    --font-size-base: 16px;
  }
  
  body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: var(--font-size-base);
    font-family: Arial, sans-serif;
    line-height: 1.6;
    padding: 20px;
    max-width: 900px;
    margin: auto;
  }
  
  header {
    background-color: var(--header-bg);
    padding: 1em;
    border-bottom: 3px solid var(--border-color);
    text-align: center;
  }
  
  h1, h2 {
    color: var(--link-color);
  }
  
  button#toggle-contrast {
    background-color: var(--link-color);
    color: white;
    border: none;
    padding: 10px 16px;
    margin-bottom: 1em;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
  }
  
  button#toggle-contrast:focus {
    outline: 3px solid #333;
    outline-offset: 3px;
  }
  
  img {
    border: 5px solid var(--border-color);
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    display: block;
    margin: 1em auto;
  }
  
  footer {
    border-top: 3px solid var(--border-color);
    text-align: center;
    padding: 1em;
    margin-top: 2em;
    color: var(--link-color);
  }
  
  /* Modo alto contraste */
  body.high-contrast {
    --bg-color: #000;
    --text-color: #fff;
    --link-color: #0ff;
    --header-bg: #111;
    --border-color: #0ff;
    background-color: var(--bg-color);
    color: var(--text-color);
  }
  /* Botão de voltar ao topo */
#topo {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background-color: #ff6f91;
  color: #fff;
  border: none;
  padding: 12px 18px;
  border-radius: 50px;
  font-size: 1rem;
  cursor: pointer;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  display: none;
  transition: background-color 0.3s ease, transform 0.3s ease;
  z-index: 999;
}

#topo:hover {
  background-color: #ff4b91;
  transform: scale(1.1);
}