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/SignalsDemo.vue

@@ -296,7 +296,7 @@ reset()
 .terminal-window {
   background: #000;
   border: 1px solid #27272a;
-  border-radius: 8px;
+  border-radius: 6px;
   height: 200px;
   display: flex;
   flex-direction: column;
@@ -325,7 +325,7 @@ reset()
   padding: 15px;
   flex: 1;
   font-size: 14px;
-  overflow-y: auto;
+  
 }
 
 .term-line {