html {
  height: 100%;
  min-height: 100%;
}

body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f5f5f5;
  color: #333;
}

header {
  background: #000000;
  color: white;
  padding: 1rem;
  text-align: center;
}

nav ul {
  display: flex;
  justify-content: center;
  gap: 2rem;
  list-style: none;
  padding: 0;
  margin-top: 1rem;
}

nav li {
  cursor: pointer;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  background-color: #616161;
  transition: background-color 0.3s;
}

nav li:hover {
  background-color: #00eeff;
}

main {
  padding: 2rem;
  
}

.secao {
  display: none;
}

.secao.ativa {
  display: block;
}

article {
  background: white;
  padding: 1rem;
  margin-bottom: 1rem;
  border-radius: 8px;
  text-decoration: none;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

footer {
  background: #333;
  color: white;
  text-align: center;
  padding: 1rem;
  margin-top: 2rem;
  position: fixed;
  width: 100%;
  bottom: 0;
}