:root { --qsn-h: 64px; }

html { scroll-padding-top: calc(var(--qsn-h) + 24px); }

.toc { top: calc(var(--qsn-h) + 24px); max-height: calc(100vh - var(--qsn-h) - 48px); }

.toc .qsn-sep { margin: 18px 10px 0; border: 0; border-top: 1px solid var(--q-line); }

.qsn {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--qsn-h);
  background: var(--q-bg);
  border-bottom: 1px solid var(--q-line);
  font: 600 15px/1 "Microsoft JhengHei", "PingFang TC", sans-serif;
}

.qsn-in {
  display: flex;
  align-items: center;
  gap: 24px;
  max-width: 1440px;
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  box-sizing: border-box;
}

.qsn a { color: var(--q-ink-2); text-decoration: none; }

.qsn img { display: inline-block; max-width: none; }

.qsn .qsn-logo { display: flex; align-items: center; gap: 10px; color: var(--q-ink); font-size: 18px; font-weight: 900; }

.qsn-logo img { width: 32px; height: 32px; }

.qsn-links { display: flex; align-self: stretch; }

.qsn-links a { position: relative; display: inline-flex; align-items: center; padding: 0 14px; white-space: nowrap; transition: color .15s; }

.qsn-links a::after { content: ""; position: absolute; left: 14px; right: 14px; bottom: 0; height: 2px; border-radius: 2px; }

.qsn-links a:hover, .qsn-links a:focus-visible, .qsn-links a[aria-current] { color: var(--q-ink); }

.qsn-links a:focus-visible { outline: none; }

.qsn-links a:focus-visible::after { background: var(--q-ink-3); }

.qsn-links a[aria-current]::after { background: var(--q-accent); }

.qsn-logo:focus-visible, .qsn-dl:focus-visible { outline: 2px solid var(--q-accent); outline-offset: 3px; border-radius: 10px; }

.qsn .qsn-dl {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 10px;
  background: var(--q-accent);
  color: var(--q-accent-ink);
  font-size: 14px;
  font-weight: 700;
  white-space: nowrap;
}

.qsn-dl img { width: 16px; height: 16px; }

@media (max-width: 760px) {
  .qsn-in { gap: 12px; padding: 0 16px; }
  .qsn-links { display: none; }
  .qsn .qsn-dl { padding: 0 14px; }
}