style: 优化仪表盘外层工作区边框布局使其贴合视口平铺撑满

frontend/src/views/Dashboard/DashboardLayout.css

@@ -1,11 +1,11 @@
 .page-shell {
   display: grid;
   grid-template-rows: auto minmax(0, 1fr);
-  gap: 16px;
+  gap: 0;
   width: 100%;
-  max-width: 1600px;
+  max-width: 100%;
   height: 100dvh;
-  padding: 24px;
+  padding: 0;
   overflow: hidden;
 }
 
@@ -56,10 +56,10 @@
   grid-template-columns: minmax(0, 1fr) 200px;
   grid-template-areas: "main submenu";
   gap: 0;
-  border: 1px solid #e2e8f2;
-  border-radius: 20px;
+  border: none;
+  border-radius: 0;
   background: #ffffff;
-  box-shadow: 0 10px 30px rgba(31, 50, 87, 0.04);
+  box-shadow: none;
   overflow: hidden;
   min-height: 0;
 }
@@ -72,7 +72,7 @@
   overscroll-behavior: contain;
   scrollbar-width: none;
   -ms-overflow-style: none;
-  border-radius: 18px;
+  border-radius: 0;
 }
 
 .dashboard-content::-webkit-scrollbar {
@@ -202,7 +202,7 @@
     flex-direction: column;
     height: auto;
     min-height: 100dvh;
-    padding: 16px;
+    padding: 0;
     overflow: visible;
   }