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/frontend-evolution/SliceRequestDemo.vue

@@ -255,12 +255,10 @@ const resetStats = () => {
 <style scoped>
 .slice-request-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;
 }
 
 /* 标题区 */
@@ -320,8 +318,8 @@ const resetStats = () => {
 .mode-card {
   background: var(--vp-c-bg);
   border: 2px solid var(--vp-c-divider);
-  border-radius: 8px;
-  padding: 1rem;
+  border-radius: 6px;
+  padding: 0.75rem;
   text-align: center;
   cursor: pointer;
   transition: all 0.2s;
@@ -382,9 +380,9 @@ const resetStats = () => {
   justify-content: space-between;
   gap: 1rem;
   margin-bottom: 1rem;
-  padding: 1rem;
+  padding: 0.75rem;
   background: var(--vp-c-bg);
-  border-radius: 8px;
+  border-radius: 6px;
   border: 2px solid var(--vp-c-divider);
 }
 
@@ -481,8 +479,8 @@ const resetStats = () => {
 
 .stat-item {
   background: var(--vp-c-bg);
-  border-radius: 8px;
-  padding: 1rem;
+  border-radius: 6px;
+  padding: 0.75rem;
   text-align: center;
   border: 2px solid var(--vp-c-divider);
 }