/* ─── HEADER ─────────────────────────────────────────────────── */
.app-header {
  height: var(--header-height);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  padding: 0 16px 0 12px;
  gap: 8px;
  flex-shrink: 0;
  position: relative;
  z-index: 10;
}

/* ─── LEFT ───────────────────────────────────────────────────── */
.header-left {
  display: flex;
  align-items: center;
  gap: 10px;
  width: var(--sidebar-width);
  flex-shrink: 0;
  padding-right: 8px;
}

.hamburger-btn {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 4.5px;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  padding: 6px;
  flex-shrink: 0;
  transition: background var(--transition-fast);
}

.hamburger-btn:hover {
  background: var(--bg-hover);
}

.ham-line {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: background var(--transition-fast);
}

.hamburger-btn:hover .ham-line {
  background: var(--text-primary);
}

.app-wordmark {
  font-size: var(--text-md);
  font-weight: var(--weight-semibold);
  letter-spacing: -0.3px;
  line-height: 1;
}

.wordmark-tone {
  color: var(--text-primary);
}

.wordmark-scout {
  color: var(--accent);
}

.active-module-badge {
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  color: var(--text-tertiary);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  padding-left: 4px;
  border-left: 1px solid var(--border-default);
  margin-left: 2px;
  line-height: 1;
}

/* ─── CENTER TABS ────────────────────────────────────────────── */
.header-tabs {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: none;
  min-height: var(--header-height);
  padding: 0 8px;
}

.header-tabs::-webkit-scrollbar {
  display: none;
}

.header-tab {
  display: inline-flex;
  align-items: center;
  height: 28px;
  padding: 0 12px;
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  white-space: nowrap;
  cursor: pointer;
  border: none;
  background: none;
  transition: color var(--transition-fast), background var(--transition-fast);
  position: relative;
}

.header-tab:hover {
  color: var(--text-primary);
  background: var(--bg-hover);
}

.header-tab.active {
  color: var(--text-primary);
  background: var(--bg-active);
}

.header-tab.active::after {
  content: '';
  position: absolute;
  bottom: -14px;
  left: 12px;
  right: 12px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px 2px 0 0;
}

.header-tabs-empty {
  font-size: var(--text-sm);
  color: var(--text-disabled);
  padding: 0 12px;
}

/* ─── RIGHT ──────────────────────────────────────────────────── */
.header-right {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
  flex-shrink: 0;
}

.header-icon-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.header-icon-btn:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}