/* ============================================
   Header & Toolbar
   ============================================ */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
  height: 42px;
  padding: 0 20px;
  border-bottom: 1px solid var(--border-color);
  position: relative;
  z-index: 30;
}

.header-left {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.header-right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex: 1;
  gap: 8px;
  height: 42px;
  z-index: 100;
  font-family: var(--font-mono);
  font-size: 13px;
}

/* ---- Toolbar ---- */
#toolbar {
  display: flex;
  padding: 0 10px;
  border-bottom: 1px solid var(--border-color);
  justify-content: center;
  align-items: center;
  flex: 1;
  height: 42px;
  gap: 2px;
}

.tool-item {
  width: 32px;
  height: 32px;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
  padding: 4px;
  border-radius: var(--radius-sm);
  user-select: none;
  opacity: 0.65;
}

.tool-item:hover { opacity: 1; background: var(--bg-hover); }
.tool-item.active { background: var(--bg-hover) !important; opacity: 1; }
.tool-item#showHistoryGraphics { margin-right: 12px; opacity: 0.85; }
.tool-item#showHistoryGraphics:hover { opacity: 1; }

#eye.show { display: inline-block; }
#eye.hide { display: none; }
#eyeClose.show { display: inline-block; }
#eyeClose.hide { display: none; }