body.light* {
  box-sizing: border-box;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px;
}

header {
  flex-direction: column;
  gap: 12px;
  padding: 16px;
}

nav {
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px;
}

nav button {
  font-size: 13px;
  padding: 8px 12px;
  white-space: nowrap;
}

@media (min-width: 640px) {
  header {
    flex-direction: row;
  }
  nav {
    gap: 8px;
  }
}