fix: nested split pane flex squeezing and add divider drag resize

src/renderer/css/split.css

@@ -14,8 +14,11 @@
 
 .split-container {
   display: flex;
+  flex: 1 1 0%;
   width: 100%;
   height: 100%;
+  min-width: 0;
+  min-height: 0;
   overflow: hidden;
   position: relative;
 }
@@ -29,14 +32,14 @@
 }
 
 .split-pane {
-  flex: 1;
+  flex: 1 1 0%;
   display: flex;
   position: relative;
   overflow: hidden;
   border: 1px solid transparent;
   transition: border-color 0.15s ease, box-shadow 0.15s ease;
-  min-width: 120px;
-  min-height: 80px;
+  min-width: 0;
+  min-height: 0;
 }
 
 .split-pane.focused {
@@ -49,6 +52,7 @@
   height: 100%;
   padding: 6px 10px;
   overflow: hidden;
+  box-sizing: border-box;
 }
 
 .xterm {
@@ -65,19 +69,24 @@
 .split-divider {
   background: var(--border-color);
   z-index: 10;
-  transition: background 0.2s ease;
+  flex-shrink: 0;
+  flex-grow: 0;
+  transition: background 0.15s ease, box-shadow 0.15s ease;
+  position: relative;
 }
 
 .split-container.horizontal > .split-divider {
-  width: 2px;
+  width: 4px;
   cursor: col-resize;
 }
 
 .split-container.vertical > .split-divider {
-  height: 2px;
+  height: 4px;
   cursor: row-resize;
 }
 
-.split-divider:hover {
+.split-divider:hover,
+.split-divider.dragging {
   background: var(--accent-color);
+  box-shadow: 0 0 10px var(--accent-glow);
 }

src/renderer/js/split-manager.js

@@ -8,7 +8,7 @@ export class TabSplitTree {
     this.onEmpty = options.onEmpty || (() => {});
     this.onTitleChange = options.onTitleChange || (() => {});
 
-    this.terminals = new Map(); // id -> TerminalView
+    this.terminals = new Map(); // id -> { termView, paneElement, parentElement }
     this.activeTerminal = null;
 
     this.rootElement = document.createElement('div');
@@ -62,10 +62,14 @@ export class TabSplitTree {
     const currentPane = currentInfo.paneElement;
     const parent = currentPane.parentElement;
 
-    // 创建一个新的 split-container 容器替换原有 pane，实现嵌套分屏
+    // 创建一个新的 split-container 容器替换原有 pane，实现嵌套等比分屏
     const splitWrapper = document.createElement('div');
     splitWrapper.className = `split-container ${direction}`;
     
+    // 继承原窗格在祖父容器中的 flex 权重
+    splitWrapper.style.flex = currentPane.style.flex || '1 1 0%';
+    currentPane.style.flex = '1 1 0%';
+
     parent.replaceChild(splitWrapper, currentPane);
     splitWrapper.appendChild(currentPane);
 
@@ -76,6 +80,11 @@ export class TabSplitTree {
 
     // 添加新窗格
     const newTerm = this.addPane(splitWrapper, direction);
+    const newPane = this.terminals.get(newTerm.id).paneElement;
+    newPane.style.flex = '1 1 0%';
+
+    // 为分割线绑定拖拽调节事件
+    this.setupDividerDrag(divider, currentPane, newPane, direction);
 
     // 刷新自适应尺寸
     setTimeout(() => {
@@ -84,6 +93,43 @@ export class TabSplitTree {
     }, 50);
   }
 
+  setupDividerDrag(divider, firstElement, secondElement, direction) {
+    const isHorizontal = direction === 'horizontal';
+
+    const onMouseDown = (e) => {
+      e.preventDefault();
+      divider.classList.add('dragging');
+      const startPos = isHorizontal ? e.clientX : e.clientY;
+      const firstSize = isHorizontal ? firstElement.offsetWidth : firstElement.offsetHeight;
+      const secondSize = isHorizontal ? secondElement.offsetWidth : secondElement.offsetHeight;
+
+      const onMouseMove = (moveEvent) => {
+        const currentPos = isHorizontal ? moveEvent.clientX : moveEvent.clientY;
+        const delta = currentPos - startPos;
+        const newFirst = firstSize + delta;
+        const newSecond = secondSize - delta;
+
+        if (newFirst > 50 && newSecond > 50) {
+          firstElement.style.flex = `${newFirst} ${newFirst} 0%`;
+          secondElement.style.flex = `${newSecond} ${newSecond} 0%`;
+          this.fitAll();
+        }
+      };
+
+      const onMouseUp = () => {
+        divider.classList.remove('dragging');
+        window.removeEventListener('mousemove', onMouseMove);
+        window.removeEventListener('mouseup', onMouseUp);
+        this.fitAll();
+      };
+
+      window.addEventListener('mousemove', onMouseMove);
+      window.addEventListener('mouseup', onMouseUp);
+    };
+
+    divider.addEventListener('mousedown', onMouseDown);
+  }
+
   setActiveTerminal(termView) {
     this.activeTerminal = termView;
 
@@ -110,8 +156,30 @@ export class TabSplitTree {
     const parent = pane.parentElement;
 
     this.terminals.delete(termId);
+
+    // 找到相邻的分割线并移除
+    const prev = pane.previousElementSibling;
+    const next = pane.nextElementSibling;
+    if (prev && prev.classList.contains('split-divider')) {
+      prev.remove();
+    } else if (next && next.classList.contains('split-divider')) {
+      next.remove();
+    }
+
     pane.remove();
 
+    // 如果非根容器中仅剩 1 个有效窗格，消除冗余包裹层将其提升至上一层
+    if (parent !== this.rootElement && parent.parentElement) {
+      const remainingChildren = Array.from(parent.children).filter(
+        (el) => !el.classList.contains('split-divider')
+      );
+      if (remainingChildren.length === 1) {
+        const singleChild = remainingChildren[0];
+        singleChild.style.flex = parent.style.flex || '1 1 0%';
+        parent.parentElement.replaceChild(singleChild, parent);
+      }
+    }
+
     if (this.terminals.size === 0) {
       this.onEmpty();
       return;
@@ -121,7 +189,7 @@ export class TabSplitTree {
     const nextTerm = this.terminals.values().next().value.termView;
     this.setActiveTerminal(nextTerm);
     nextTerm.focus();
-    this.fitAll();
+    setTimeout(() => this.fitAll(), 40);
   }
 
   fitAll() {