body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

footer {
  margin-top: auto;
}

#filter {
  width: 50%;
}

#menu {
  display: flex;
  list-style: none;
}

a {
  color: #259dff;
  text-decoration: none;
}

#menu2 {
  display: none;
}

.filtering #menu2 {
  display: block;
}

.filtering #menu {
  display: none;
}