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/cache-design/CacheHierarchyDemo.vue

@@ -141,10 +141,10 @@ const simulateFlow = () => {
 <style scoped>
 .cache-hierarchy-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;
+  padding: 0.75rem;
+  margin: 0.5rem 0;
   max-width: 600px;
 }
 
@@ -187,8 +187,8 @@ const simulateFlow = () => {
   max-width: 400px;
   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 0.3s;
 }
@@ -262,8 +262,8 @@ const simulateFlow = () => {
 
 .data-flow {
   background: var(--vp-c-bg);
-  border-radius: 8px;
-  padding: 1rem;
+  border-radius: 6px;
+  padding: 0.75rem;
   margin-bottom: 1rem;
   border: 1px solid var(--vp-c-divider);
 }
@@ -288,7 +288,7 @@ const simulateFlow = () => {
   gap: 1rem;
   padding: 0.75rem 1rem;
   background: var(--vp-c-bg-soft);
-  border-radius: 8px;
+  border-radius: 6px;
   border: 2px solid var(--vp-c-divider);
   transition: all 0.3s;
   width: 100%;
@@ -335,7 +335,7 @@ const simulateFlow = () => {
   background: var(--vp-c-brand);
   color: white;
   border: none;
-  border-radius: 8px;
+  border-radius: 6px;
   font-size: 0.9rem;
   font-weight: 600;
   cursor: pointer;
@@ -349,8 +349,8 @@ const simulateFlow = () => {
 
 .comparison-table {
   background: var(--vp-c-bg);
-  border-radius: 8px;
-  padding: 1rem;
+  border-radius: 6px;
+  padding: 0.75rem;
   margin-bottom: 1rem;
   border: 1px solid var(--vp-c-divider);
 }