style: update border-radius and padding values across components

- standardize border-radius from 8px to 6px for consistent styling
- adjust padding values from 1rem to 0.75rem for better visual hierarchy
- remove redundant overflow-y properties for cleaner code

docs/.vitepress/theme/components/appendix/terminal-intro/ArchitectureDemo.vue

@@ -596,7 +596,7 @@ const reset = () => {
 .node {
   background: #18181b;
   border: 2px solid #27272a;
-  border-radius: 8px;
+  border-radius: 6px;
   width: 140px;
   height: 130px;
   display: flex;
@@ -757,7 +757,7 @@ const reset = () => {
   gap: 20px;
   background: #18181b;
   padding: 20px;
-  border-radius: 8px;
+  border-radius: 6px;
   border: 1px solid #27272a;
 }