fix: 框选模式改为任意位置拖拽均可画矩形选择

- 移除 block 元素上的 click 事件（单点选中）
- mousedown 不再跳过 block 元素，任意位置均可开始拖拽
- mouseup 根据移动距离判断：>3px 为框选，<=3px 为单击选中
- 单击空白取消选中，Ctrl+单击追加选中
- 添加列表项和变量块 CSS 样式注入

web/src/components/DocRenderer.vue

@@ -126,6 +126,18 @@ function injectStyles(doc: Document) {
       outline-offset: 2px;
       background-color: rgba(154, 161, 173, 0.06) !important;
     }
+    [data-block-index].block-variable {
+      outline: 2px solid rgba(26, 140, 74, 0.5) !important;
+      outline-offset: 2px;
+      background-color: rgba(26, 140, 74, 0.06) !important;
+    }
+    .block-list-item.list-unordered::before {
+      content: "\\2022";
+      display: inline-block;
+      width: 1em;
+      margin-left: -1em;
+      color: #333;
+    }
   `
   doc.head.appendChild(style)
 }
@@ -147,126 +159,137 @@ function bindIframeEvents(doc: Document) {
     el.addEventListener('mouseleave', () => {
       el.classList.remove('hover-highlight')
     })
-
-    // 点击选中
-    el.addEventListener('click', (e: Event) => {
-      if (mode.value !== 'select') return
-      const mouseEvent = e as MouseEvent
-      const index = parseInt(el.getAttribute('data-block-index') || '')
-      if (isNaN(index)) return
-
-      if (mouseEvent.ctrlKey || mouseEvent.metaKey) {
-        // Ctrl+点击：追加/取消选中
-        if (selectedIndices.value.has(index)) {
-          selectedIndices.value.delete(index)
-          el.classList.remove('block-selected')
-        } else {
-          selectedIndices.value.add(index)
-          el.classList.add('block-selected')
-        }
-        selectedIndices.value = new Set(selectedIndices.value)
-      } else {
-        // 普通点击：单选
-        clearAllSelection(doc)
-        selectedIndices.value = new Set([index])
-        el.classList.add('block-selected')
-      }
-      emitBlockSelect()
-    })
   })
 
-  // 拖拽框选
+  // 统一处理单击选中 与 拖拽框选：在 mousedown 记录起点，mouseup 时根据移动距离判断
+  let mouseDownTarget: HTMLElement | null = null
+  let mouseMoved = false
+
   doc.addEventListener('mousedown', (e: MouseEvent) => {
     if (mode.value !== 'select') return
-    // 只在文档区域（非 block 元素上）开始拖拽
-    const target = e.target as HTMLElement
-    if (target.hasAttribute('data-block-index')) return
-
-    isDragging.value = true
-    showSelectionRect.value = true
+    mouseDownTarget = e.target as HTMLElement
+    mouseMoved = false
+    isDragging.value = false
+    showSelectionRect.value = false
     dragStart.value = { x: e.clientX, y: e.clientY }
     selectionRect.value = { left: e.clientX, top: e.clientY, width: 0, height: 0 }
+
+    // 非 Ctrl 按下时，提前清除旧选中（给用户即时的视觉反馈）
+    if (!(e.ctrlKey || e.metaKey)) {
+      clearAllSelection(doc)
+      selectedIndices.value = new Set()
+    }
   })
 
   doc.addEventListener('mousemove', (e: MouseEvent) => {
-    if (!isDragging.value || mode.value !== 'select') return
-    selectionRect.value = {
-      left: Math.min(dragStart.value.x, e.clientX),
-      top: Math.min(dragStart.value.y, e.clientY),
-      width: Math.abs(e.clientX - dragStart.value.x),
-      height: Math.abs(e.clientY - dragStart.value.y),
+    if (mode.value !== 'select') return
+    if (dragStart.value.x === 0 && dragStart.value.y === 0) return
+    const dx = Math.abs(e.clientX - dragStart.value.x)
+    const dy = Math.abs(e.clientY - dragStart.value.y)
+    if (dx > 3 || dy > 3) {
+      mouseMoved = true
+      // 开始显示框选矩形
+      if (!isDragging.value) {
+        isDragging.value = true
+        showSelectionRect.value = true
+      }
+      selectionRect.value = {
+        left: Math.min(dragStart.value.x, e.clientX),
+        top: Math.min(dragStart.value.y, e.clientY),
+        width: Math.abs(e.clientX - dragStart.value.x),
+        height: Math.abs(e.clientY - dragStart.value.y),
+      }
     }
   })
 
   doc.addEventListener('mouseup', (e: MouseEvent) => {
-    if (!isDragging.value) return
-    isDragging.value = false
-    showSelectionRect.value = false
+    if (mode.value !== 'select') return
 
-    // 计算拖拽距离，判断是框选还是取消
-    const dx = Math.abs(e.clientX - dragStart.value.x)
-    const dy = Math.abs(e.clientY - dragStart.value.y)
-    if (dx < 5 && dy < 5) {
-      // 微小移动，忽略
-      selectionRect.value = { left: 0, top: 0, width: 0, height: 0 }
-      return
-    }
+    if (mouseMoved && isDragging.value) {
+      // 拖拽框选：计算选区覆盖的 blocks
+      isDragging.value = false
+      showSelectionRect.value = false
 
-    // 计算选区覆盖的 blocks
-    const rect = iframeRef.value?.getBoundingClientRect()
-    if (!rect) return
-    clearAllSelection(doc)
-    const newSelected = new Set<number>()
-
-    blocks.forEach(el => {
-      const blockRect = el.getBoundingClientRect()
-      // 判断 block 是否与选择矩形相交
+      const iframeRect = iframeRef.value?.getBoundingClientRect()
+      if (!iframeRect) {
+        dragStart.value = { x: 0, y: 0 }
+        return
+      }
+      const newSelected = new Set(selectedIndices.value)
       const selRect = {
         left: selectionRect.value.left,
         top: selectionRect.value.top,
         right: selectionRect.value.left + selectionRect.value.width,
         bottom: selectionRect.value.top + selectionRect.value.height,
       }
-      const bRect = {
-        left: blockRect.left,
-        top: blockRect.top,
-        right: blockRect.right,
-        bottom: blockRect.bottom,
-      }
-      if (
-        selRect.left < bRect.right &&
-        selRect.right > bRect.left &&
-        selRect.top < bRect.bottom &&
-        selRect.bottom > bRect.top
-      ) {
-        const index = parseInt(el.getAttribute('data-block-index') || '')
-        if (!isNaN(index)) {
-          newSelected.add(index)
-          el.classList.add('block-selected')
+      blocks.forEach(el => {
+        const br = el.getBoundingClientRect()
+        if (
+          selRect.left < br.right &&
+          selRect.right > br.left &&
+          selRect.top < br.bottom &&
+          selRect.bottom > br.top
+        ) {
+          const index = parseInt(el.getAttribute('data-block-index') || '')
+          if (!isNaN(index)) {
+            newSelected.add(index)
+            el.classList.add('block-selected')
+          }
         }
+      })
+      selectedIndices.value = newSelected
+      selectionRect.value = { left: 0, top: 0, width: 0, height: 0 }
+
+      if (newSelected.size > 0) {
+        showContextMenu.value = true
+        contextMenuPos.value = { x: e.clientX, y: e.clientY + 10 }
+      } else {
+        showContextMenu.value = false
       }
-    })
-
-    selectedIndices.value = newSelected
-    selectionRect.value = { left: 0, top: 0, width: 0, height: 0 }
-
-    if (newSelected.size > 0) {
-      showContextMenu.value = true
-      contextMenuPos.value = { x: e.clientX, y: e.clientY + 10 }
-    }
-    emitBlockSelect()
-  })
-
-  // 点击空白处取消选中
-  doc.addEventListener('click', (e: MouseEvent) => {
-    if (mode.value !== 'select') return
-    const target = e.target as HTMLElement
-    if (!target.hasAttribute('data-block-index') && !isDragging.value) {
-      clearAllSelection(doc)
-      selectedIndices.value = new Set()
-      showContextMenu.value = false
       emitBlockSelect()
+    } else {
+      // 短点击（没有拖动）：单击选中或取消
+      isDragging.value = false
+      showSelectionRect.value = false
+      selectionRect.value = { left: 0, top: 0, width: 0, height: 0 }
+
+      const target = e.target as HTMLElement
+      const blockEl = target.closest?.('[data-block-index]') as HTMLElement | null
+      if (blockEl) {
+        const index = parseInt(blockEl.getAttribute('data-block-index') || '')
+        if (!isNaN(index)) {
+          if (e.ctrlKey || e.metaKey) {
+            // Ctrl+点击：追加/取消
+            if (selectedIndices.value.has(index)) {
+              selectedIndices.value.delete(index)
+              blockEl.classList.remove('block-selected')
+            } else {
+              selectedIndices.value.add(index)
+              blockEl.classList.add('block-selected')
+            }
+            selectedIndices.value = new Set(selectedIndices.value)
+          } else {
+            // 普通点击：单选该块（已在 mousedown 清空，直接添加）
+            selectedIndices.value = new Set([index])
+            blockEl.classList.add('block-selected')
+          }
+          emitBlockSelect()
+          if (selectedIndices.value.size > 0) {
+            showContextMenu.value = true
+            contextMenuPos.value = { x: e.clientX, y: e.clientY + 10 }
+          }
+        }
+      } else {
+        // 点击空白区域：取消所有选中
+        clearAllSelection(doc)
+        selectedIndices.value = new Set()
+        showContextMenu.value = false
+        emitBlockSelect()
+      }
     }
+
+    dragStart.value = { x: 0, y: 0 }
+    mouseMoved = false
   })
 }