:root {
  --site-header-bg: rgba(11, 16, 24, .94);
  --site-header-line: rgba(160, 176, 196, .2);
  --site-header-muted: #9aa7b8;
  --site-header-ink: #f5f7fb;
  --site-header-accent: #00d8ee;
}

.site-header {
  position: relative;
  z-index: 10;
  width: min(1480px, calc(100% - 32px));
  min-height: 76px;
  margin: 0 auto 20px;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border: 1px solid var(--site-header-line);
  border-radius: 8px;
  background: linear-gradient(105deg, rgba(10, 19, 29, .98), var(--site-header-bg));
  box-shadow: 0 18px 45px rgba(0, 0, 0, .22);
  overflow: visible;
}

.app-shell > .site-header,
.admin-shell > .site-header {
  width: 100%;
}

.site-brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 13px;
  color: inherit;
  text-decoration: none;
}

.site-brand-logo { width: 74px; height: 48px; object-fit: contain; flex: 0 0 auto; }
.site-brand-copy { min-width: 0; display: grid; gap: 5px; }
.site-brand-eyebrow { color: var(--site-header-accent); font-size: 11px; font-weight: 800; letter-spacing: .08em; white-space: nowrap; }
.site-brand-title { color: var(--site-header-ink); font-size: 13px; font-weight: 700; white-space: nowrap; }

.site-nav, .site-utilities { display: flex; align-items: center; gap: 4px; }
.site-nav { margin-left: auto; }
.site-nav-link {
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: 6px;
  padding: 0 12px;
  color: var(--site-header-muted);
  background: transparent;
  font-size: 13px;
  font-weight: 750;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s ease, background .18s ease, border-color .18s ease;
}
.site-nav-link:hover, .site-nav-link.active { color: var(--site-header-ink); background: rgba(255, 255, 255, .08); border-color: var(--site-header-line); }
.site-nav-link.active { color: var(--site-header-accent); }
.site-nav-link.tab-button.active {
  background: linear-gradient(180deg, var(--site-header-accent) 0%, #00a9c2 100%);
  border-color: rgba(255, 255, 255, .2);
  color: #031411;
  font-weight: 800;
}
.site-nav-link.tab-button.active:hover {
  background: linear-gradient(180deg, #2ae0f2 0%, #00a9c2 100%);
  border-color: rgba(255, 255, 255, .28);
  color: #031411;
}
.site-settings-tab { margin-left: 4px; }
.site-utilities { padding-left: 8px; border-left: 1px solid var(--site-header-line); }
.site-utility-button { width: 30px; height: 30px; min-height: 30px; display: grid; place-items: center; border: 1px solid transparent; border-radius: 6px; padding: 0; background: transparent; opacity: .42; cursor: not-allowed; }
.site-utility-button img { width: 16px; height: 16px; filter: invert(82%); }
.site-utility-button:hover { transform: none; }
.site-header .course-progress { position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; background: transparent; }
.site-header .course-progress span { display: block; width: 0; height: 100%; background: var(--site-header-accent); transition: width .24s ease; }

@media (max-width: 980px) {
  .site-header { flex-wrap: wrap; gap: 8px 14px; padding: 11px 14px; }
  .site-nav { order: 3; width: 100%; margin-left: 0; overflow-x: auto; }
  .site-utilities { margin-left: auto; }
}

@media (max-width: 560px) {
  .site-header { width: calc(100% - 20px); min-height: 66px; margin-bottom: 14px; padding: 9px 10px; }
  .site-brand-logo { width: 56px; height: 38px; }
  .site-brand-eyebrow { font-size: 9px; }
  .site-brand-title { font-size: 11px; }
  .site-nav-link { min-height: 32px; padding: 0 8px; font-size: 11px; }
  .site-utility-button { width: 25px; height: 25px; min-height: 25px; }
}