.side-nav {
  width: 52px;
  background: var(--bg-panel);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 8px;
  gap: 4px;
  flex-shrink: 0;
  z-index: 10;
}

.side-nav-top {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.side-nav-item {
  width: 40px;
  height: 40px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 16px;
  transition: all 0.15s;
  position: relative;
}

.side-nav-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.side-nav-item.active {
  background: var(--bg-active);
  color: #fff;
}

.side-nav-item.active::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 20px;
  background: var(--accent-blue);
  border-radius: 0 2px 2px 0;
}

.nav-tooltip {
  position: absolute;
  left: 52px;
  background: var(--bg-panel);
  border: 1px solid #454545;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 12px;
  color: var(--text-primary);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  z-index: 50;
}

.side-nav-item:hover .nav-tooltip { opacity: 1; }

.side-nav-bottom {
  margin-top: auto;
  padding: 8px 0;
}

.logo-mini {
  width: 28px;
  height: 28px;
  background: var(--accent-blue);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  color: #fff;
}

.main-wrapper {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  position: relative;
  min-width: 0;
}

.title-bar {
  height: 36px;
  width: 100%;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  gap: 12px;
  flex-shrink: 0;
}

.title-bar-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-direction: row-reverse;
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-secondary);
}

.breadcrumbs .crumb { color: var(--text-primary); }
.breadcrumbs .sep { color: #555; }

.replace-hint {
  font-size: 12px;
  color: var(--text-secondary);
  display: none;
  margin-left: 12px;
  padding-left: 12px;
  border-left: 1px solid var(--border-color);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.mode-container {
  flex: 1;
  min-height: 0;
  display: none;
  flex-direction: column;
  overflow: hidden;
  width: 100%;
}

.mode-container.active { display: flex; }