fix(distribution-admin): 优化左侧导航栏为固定不随页面滚动，独立右侧主体滚动区

distribution-admin/src/style.css

@@ -8,17 +8,56 @@
   box-sizing: border-box;
 }
 
-body {
+html,
+body,
+#root {
+  height: 100%;
   margin: 0;
+  padding: 0;
 }
 
 .app {
+  height: 100vh;
   min-height: 100vh;
+  overflow: hidden;
+  display: flex;
+  flex-direction: row;
+}
+
+.app-sider {
+  height: 100vh !important;
+  position: sticky !important;
+  top: 0;
+  left: 0;
+  overflow: hidden;
+  flex-shrink: 0;
+  z-index: 100;
+  box-shadow: 2px 0 8px rgba(0, 0, 0, 0.12);
+}
+
+.app-sider .ant-layout-sider-children {
+  display: flex;
+  flex-direction: column;
+  height: 100vh;
+  overflow-y: auto;
+  overflow-x: hidden;
+}
+
+.app-sider .ant-layout-sider-children::-webkit-scrollbar {
+  width: 4px;
+}
+.app-sider .ant-layout-sider-children::-webkit-scrollbar-thumb {
+  background: rgba(255, 255, 255, 0.2);
+  border-radius: 2px;
+}
+.app-sider .ant-layout-sider-children::-webkit-scrollbar-track {
+  background: transparent;
 }
 
 .brand {
   height: 64px;
-  padding: 20px 20px;
+  line-height: 64px;
+  padding: 0 20px;
   color: #fff;
   font-size: 16px;
   font-weight: 600;
@@ -26,9 +65,24 @@ body {
   display: flex;
   align-items: center;
   gap: 10px;
+  flex-shrink: 0;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
+}
+
+.app-layout {
+  height: 100vh;
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+  min-width: 0;
+  background: #f5f7fa;
 }
 
 .header {
+  flex-shrink: 0;
+  height: 64px;
+  line-height: 64px;
   display: flex;
   align-items: center;
   justify-content: space-between;
@@ -36,6 +90,7 @@ body {
   padding: 0 24px;
   border-bottom: 1px solid #edf0f5;
   box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
+  z-index: 99;
 }
 
 .header-left {
@@ -56,6 +111,29 @@ body {
   gap: 8px;
 }
 
+.app-content {
+  flex: 1;
+  min-height: 0;
+  overflow-y: auto;
+  overflow-x: hidden;
+  background: #f5f7fa;
+}
+
+.app-content::-webkit-scrollbar {
+  width: 6px;
+  height: 6px;
+}
+.app-content::-webkit-scrollbar-thumb {
+  background: #cbd5e1;
+  border-radius: 3px;
+}
+.app-content::-webkit-scrollbar-thumb:hover {
+  background: #94a3b8;
+}
+.app-content::-webkit-scrollbar-track {
+  background: transparent;
+}
+
 .page {
   width: 100%;
   padding: 24px;