header {
  background-color: var(--c-bg1);
  padding: 5px 20px;
}

header ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 15px;
  align-items: center;
}

header ul li a {
  color: var(--c-fg0);
}

header ul li a .si {
  fill: var(--c-fg0);
}

header ul li:first-child {
  flex-grow: 1;
  font-weight: bold;
  font-size: 120%;
}

@media (max-width: 250px) {
  header ul {
    flex-direction: column;
    gap: 5px;
  }
}

main {
  max-width: 951px;
  margin: 20px auto;
  padding: 0 20px;
}

.heading_anchor {
  color: var(--c-fg2);
}