.footer {
  text-align: center;
  font-size: 0.9rem;
  font-family: var(--font-family-heading);
}

/* Fallback: footer as sibling of sidebar */
.sidebar ~ .footer {
  margin-left: 216px;
  width: calc(100% - 216px);
}

.sidebar.close ~ .footer {
  margin-left: 70px;
  width: calc(100% - 70px);
}

@media screen and (max-width: 400px) {
  .sidebar ~ .footer {
    margin-left: 240px;
    width: calc(100% - 240px);
  }
  .sidebar.close ~ .footer {
    margin-left: 78px;
    width: calc(100% - 78px);
  }
}