/* ============================================================
   侧边栏树形导航
   ============================================================ */

.sidebar-nav {
  padding: 16px 12px 32px;
}

.sidebar-tree {
  list-style: none;
  margin: 0;
  padding: 0;
}
.sidebar-tree--nested {
  padding-left: 14px;
}

.sidebar-item { margin: 1px 0; }

/* ---------- 分组 header ---------- */
.sidebar-group-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  user-select: none;
  color: var(--color-text-muted);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.6px;
  text-transform: uppercase;
  transition: background-color var(--transition-fast),
              color var(--transition-fast);
}
.sidebar-group-header:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text);
}

.sidebar-arrow {
  display: inline-block;
  position: relative;
  width: 12px;
  height: 12px;
  flex-shrink: 0;
}
.sidebar-arrow::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-left: 5px solid currentColor;
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  transform: translate(-50%, -50%);
  transition: transform var(--transition-fast);
}
.sidebar-item:not(.collapsed) > .sidebar-group-header .sidebar-arrow::before {
  transform: translate(-50%, -50%) rotate(90deg);
}

.sidebar-group-title {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 折叠时隐藏子树 */
.sidebar-item.collapsed > .sidebar-tree--nested { display: none; }

/* ---------- 叶子链接 ---------- */
.sidebar-link {
  display: block;
  position: relative;
  padding: 6px 8px 6px 26px;
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 14px;
  line-height: 1.4;
  transition: background-color var(--transition-fast),
              color var(--transition-fast);
  text-decoration: none;
}
.sidebar-link::before {
  content: '';
  position: absolute;
  left: 16px;
  top: 50%;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-text-muted);
  opacity: 0.45;
  transform: translateY(-50%);
  transition: background var(--transition-fast),
              opacity var(--transition-fast);
}
.sidebar-link:hover {
  background-color: var(--color-bg-hover);
  text-decoration: none;
}
.sidebar-link:hover::before { opacity: 1; }

.sidebar-link.active {
  background-color: var(--color-primary-bg);
  color: var(--color-primary);
  font-weight: 500;
}
.sidebar-link.active::before {
  background: var(--color-primary);
  opacity: 1;
}