feat: update layout style

src/assets/styles/index.scss

@@ -11,4 +11,13 @@ code {
     monospace;
 }
 
+*::-webkit-scrollbar {
+  width: 8px;
+  background: transparent;
+}
+*::-webkit-scrollbar-thumb {
+  border-radius: 8px;
+  background-color: rgba(#909399, 0.5);
+}
+
 @import "./layout.scss";

src/assets/styles/layout.scss

 .layout {
   width: 100%;
-  height: 100%;
+  height: 100vh;
   display: flex;
 
   &__sidebar {
     position: relative;
-    height: 100vh;
+    height: 100%;
     flex: 1 0 25%;
     max-width: 250px;
+    overflow: hidden auto;
   }
 
   &__content {
     flex: 1 1 75%;
-    padding: 20px 30px;
+    height: 100%;
     box-sizing: border-box;
+    overflow: hidden auto;
   }
 
   &__traffic {