/* 树形列表图标颜色：按功能分类 */

/* 章节图标（文件夹）- 蓝色 */
.tree-item .node-icon img[src*="book-bookmark"],
.tree-item img[src*="book-bookmark"] {
  --tree-icon-color: #4a90e2;
}

.tree-item:hover .node-icon img[src*="book-bookmark"],
.tree-item:hover img[src*="book-bookmark"] {
  filter: brightness(0) saturate(100%) invert(47%) sepia(95%) saturate(2000%) hue-rotate(195deg) brightness(0.95);
}

/* 页面图标（文档）- 绿色 */
.tree-item .node-icon img[src*="file-alt"],
.tree-item img[src*="file-alt"] {
  --tree-icon-color: #67c23a;
}

.tree-item:hover .node-icon img[src*="file-alt"],
.tree-item:hover img[src*="file-alt"] {
  filter: brightness(0) saturate(100%) invert(62%) sepia(95%) saturate(500%) hue-rotate(80deg) brightness(0.95);
}

/* 添加按钮图标 - 青色 */
#btn-add-chapter img,
.btn-icon-small[id="btn-add-chapter"] img {
  --tree-icon-color: #1abc9c;
}

#btn-add-chapter:hover img,
.btn-icon-small[id="btn-add-chapter"]:hover img {
  filter: brightness(0) saturate(100%) invert(71%) sepia(95%) saturate(500%) hue-rotate(140deg) brightness(0.95);
}

/* 删除按钮图标 - 红色 */
.btn-delete-node img {
  --tree-icon-color: #e74c3c;
}

.btn-delete-node:hover img {
  filter: brightness(0) saturate(100%) invert(24%) sepia(95%) saturate(5000%) hue-rotate(340deg) brightness(0.95);
}

/* 树形列表图标默认颜色 */
.tree-item .node-icon img,
.tree-item img.icon-16 {
  filter: brightness(0) saturate(100%) invert(60%);
  opacity: 0.8;
  transition: filter 0.2s ease, opacity 0.2s ease;
}

/* 激活状态 */
.tree-item.active .node-icon img,
.tree-item.active img.icon-16 {
  filter: brightness(0) saturate(100%) invert(47%) sepia(95%) saturate(2000%) hue-rotate(195deg) brightness(0.95);
  opacity: 1;
}