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/component-state-management/VuexPiniaDemo.vue

@@ -96,12 +96,12 @@ const activeTab = ref('pinia')
 <style scoped>
 .vuex-pinia-demo {
   border: 1px solid var(--vp-c-divider);
-  border-radius: 8px;
+  border-radius: 6px;
   background: var(--vp-c-bg-soft);
-  padding: 1rem;
-  margin: 1rem 0;
-  max-height: 600px;
-  overflow-y: auto;
+  padding: 0.75rem;
+  margin: 0.5rem 0;
+  
+  
 }
 
 .demo-header {
@@ -155,8 +155,8 @@ const activeTab = ref('pinia')
 .card {
   background: var(--vp-c-bg);
   border: 2px solid var(--vp-c-divider);
-  border-radius: 8px;
-  padding: 1rem;
+  border-radius: 6px;
+  padding: 0.75rem;
   cursor: pointer;
   transition: all 0.2s ease;
 }
@@ -225,7 +225,7 @@ const activeTab = ref('pinia')
 .code-example {
   background: var(--vp-c-bg);
   border-radius: 6px;
-  padding: 1rem;
+  padding: 0.75rem;
 }
 
 .code-title {
@@ -237,7 +237,7 @@ const activeTab = ref('pinia')
 
 .code-block {
   margin: 0;
-  padding: 1rem;
+  padding: 0.75rem;
   background: #1e1e1e;
   border-radius: 6px;
   overflow-x: auto;