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/api-design/DocumentationDemo.vue

@@ -300,7 +300,7 @@ const currentTool = computed(() =>
   gap: 8px;
   padding: 12px 16px;
   border: 2px solid var(--vp-c-divider);
-  border-radius: 8px;
+  border-radius: 6px;
   background: var(--vp-c-bg);
   cursor: pointer;
   transition: all 0.2s ease;
@@ -330,7 +330,7 @@ const currentTool = computed(() =>
 .tool-detail {
   background: var(--vp-c-bg);
   border: 1px solid var(--vp-c-divider);
-  border-radius: 8px;
+  border-radius: 6px;
   overflow: hidden;
 }