* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body { font-family: Arial, sans-serif; background: #f8f8f8; margin: 0; padding: 20px; }

    header, footer {
    background-color: #00695c;
    color: white;
    padding: 1rem;
    text-align: center;
    }

    nav a {
    margin-left: 1.5rem;
    text-decoration: none;
    color: white;
    font-weight: 500;
    }

    .filtros { margin-bottom: 20px; display: flex; gap: 10px; }
    select { padding: 5px; }
    .grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 15px; }
    .card { background: white; padding: 15px; border-radius: 10px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
    .card h3 { margin: 0; font-size: 18px; color: #333; }
    .card p { font-size: 14px; color: #555; }
    .link { color: #0077cc; text-decoration: none; font-size: 14px; }