style(docs): update brand-dimm color

docs/.vitepress/theme/styles/custom.less

@@ -12,7 +12,7 @@
     --vp-c-brand-lightest: lighten(@brand-color, 24%);
     --vp-c-brand-dark: darken(@brand-color, 8%);
     --vp-c-brand-darker: darken(@brand-color, 16%);
-    --vp-c-brand-dimm: rgba(100, 108, 255, 0.08);
+    --vp-c-brand-dimm: rgba(103, 165, 243, 0.1);
 }
 
 /**