.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  min-height: 62px;
  padding: 12px 28px;
  border-bottom: 1px solid var(--line);
  background: rgba(244, 242, 237, .96);
}

.site-header .brand {
  justify-self: start;
  font-weight: 700;
  letter-spacing: .08em;
  text-decoration: none;
}

.site-primary-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  font: 12px/1 Arial, sans-serif;
}

.site-primary-nav a,
.site-account-nav a { text-decoration: none; }

.site-primary-nav a {
  position: relative;
  padding: 10px 2px;
  color: var(--muted);
}

.site-primary-nav a:hover,
.site-primary-nav a.active { color: var(--ink); }

.site-primary-nav a.active::after {
  position: absolute;
  right: 0;
  bottom: 3px;
  left: 0;
  height: 1px;
  background: var(--ink);
  content: "";
}

.site-account-nav {
  display: flex;
  align-items: center;
  justify-self: end;
  gap: 12px;
  font: 12px/1 Arial, sans-serif;
}

.site-account-nav .button {
  display: inline-block;
  padding: 9px 13px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  cursor: pointer;
}

.site-account-nav .button.active {
  background: #fff;
  color: var(--ink);
}

.site-avatar {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background: #fff;
  font: 700 14px/1 Georgia, "Songti SC", STSong, serif;
}

@media (max-width: 760px) {
  .site-header {
    grid-template-columns: minmax(0, 1fr) auto;
    padding: 10px 18px;
  }

  .site-primary-nav {
    grid-column: 1 / -1;
    grid-row: 2;
    margin-top: 5px;
    gap: 32px;
  }

  .site-account-nav {
    grid-column: 2;
    grid-row: 1;
  }

  .site-account-nav .button { padding: 8px 10px; }
  .site-avatar { width: 32px; height: 32px; }
}