fix: handle hardcoded border color of chapter header for Feedbooks, closes #470 (#485)

apps/readest-app/src/utils/style.ts

@@ -178,7 +178,6 @@ const getLayoutStyles = (
     background: var(--background-set, none);
   }
   body *:not(a):not(#b1):not(#b1 *):not(#b2):not(#b2 *):not(.bg):not(.bg *):not(.vol):not(.vol *):not(.background):not(.background *) {
-    border-color: currentColor !important;
     ${bg === '#ffffff' ? '' : `color: inherit;`}
     ${bg === '#ffffff' ? '' : `background-color: ${bg} !important;`}
   }
@@ -227,6 +226,10 @@ const getLayoutStyles = (
   .calibre {
     color: unset;
   }
+
+  .chapterHeader {
+    border-color: unset;
+  }
 `;
 
 export const getFootnoteStyles = () => `