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/cloud-services/RegionLatencyDemo.vue

@@ -101,10 +101,10 @@ const recommendation = computed(() => {
 <style scoped>
 .region-latency-demo {
   border: 1px solid var(--vp-c-divider);
-  border-radius: 8px;
+  border-radius: 6px;
   background-color: var(--vp-c-bg-soft);
-  padding: 1rem;
-  margin: 1rem 0;
+  padding: 0.75rem;
+  margin: 0.5rem 0;
 }
 
 .user-location {
@@ -198,7 +198,7 @@ const recommendation = computed(() => {
 .bar-fill {
   height: 100%;
   background: var(--vp-c-brand);
-  border-radius: 8px;
+  border-radius: 6px;
   transition: width 0.3s;
 }