Add `filepath` style for code

_sass/addon/syntax.scss

@@ -110,6 +110,13 @@ code {
     background-color: var(--inline-code-bg);
   }
 
+  &.filepath {
+    background-color: inherit;
+    color: var(--filepath-text-color);
+    font-weight: 600;
+    padding: 0;
+  }
+
   a > &.highlighter-rouge {
     padding-bottom: 0; // show link's underlinke
     color: inherit;
@@ -119,7 +126,7 @@ code {
     border-bottom: none;
   }
 
-  blockquote &.highlighter-rouge {
+  blockquote & {
     color: inherit;
   }
 

_sass/colors/dark-syntax.scss

@@ -78,6 +78,7 @@
   --code-header-muted-color: rgb(60 60 60);
   --code-header-icon-color: rgb(86 86 86);
   --clipboard-checked-color: #2bcc2b;
+  --filepath-text-color: #bdbdbd;
 
   .highlight {
     .gp { color: #818c96; }