/* Sticky header: brand block, nav links with active underline, 한/EN segmented toggle. */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: stretch;
  height: var(--header-h);
  background: rgba(255, 255, 255, .88);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 24px;
  border-right: 1px solid var(--line);
  text-decoration: none;
  flex-shrink: 0;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border: 1.5px solid var(--ink);
  border-radius: 6px;
  font-weight: 700;
  font-size: 14px;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-name { font-size: 15px; font-weight: 700; }
.brand-sub { font-size: 9.5px; letter-spacing: .14em; color: var(--note); }

.nav {
  display: flex;
  align-items: stretch;
  padding-left: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  flex: 1;
  min-width: 0;
}
.nav::-webkit-scrollbar { display: none; }
.nav-link {
  display: flex;
  align-items: center;
  padding: 0 14px;
  font-size: var(--fs-nav);
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}
.nav-link:hover { color: var(--ink); }
.nav-link.is-active { color: var(--ink); border-bottom-color: var(--ink); }

.lang {
  display: flex;
  align-items: center;
  align-self: center;
  margin: 0 24px 0 12px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg);
  flex-shrink: 0;
}
.lang-btn {
  height: 26px;
  min-width: 36px;
  padding: 0 9px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--note);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}
.lang-btn.is-active { background: var(--navy); color: #fff; }