feat: invert PDF colors in dark theme

Author: subframe7536

src/editor/pdf.scss

@@ -1,9 +1,15 @@
-.theme-dark.pdf-dark-hover .pdf-viewer {
-  opacity: 0.7;
-  transition: opacity var(--animation);
+.theme-dark {
+  &.pdf-dark-hover .pdfViewer {
+    opacity: 0.7;
+    transition: opacity var(--animation);
 
-  &:hover {
-    opacity: 0.85;
+    &:hover {
+      opacity: 0.85;
+    }
+  }
+
+  &.pdf-dark-invert .pdfViewer .page {
+    filter: invert(1) contrast(0.8);
   }
 }
 

src/style-settings/editor.ts

@@ -914,6 +914,12 @@ export default Settings.create('maple-editor', 'Maple Editor').children([
       },
       { enable: true },
     )
+    .addClassToggle('pdf-dark-invert', {
+      title: {
+        en: 'Invert Colors in Dark Mode',
+        zh: '黑暗模式下反转颜色',
+      },
+    })
     .children([
       Settings.ofLevel(2, {
         title: { en: 'PDF Export', zh: 'PDF 导出' },